- "When someone betrays your trust, it feels like a part of you dies. For me, I guess it was the part that cared."
- — Phi to Sigma, when he tries to stop her from leaving Rhizome 9
Phi is a player in the Nonary Game: Ambidex Edition and the deuteragonist of Zero Escape: Virtue's Last Reward. She first appears in the Elevator, along with Sigma Klim, and seems to know him, or at least his name. Phi is cold and blunt, but also an intellectual and quick-thinking young woman.
Phi is a pale-skinned blue-eyed young woman with short white cropped hair. In Virtue's Last Reward, her hair is topped off with a large black flower hairpin. The flower is a black dahlia - it does not have a very pleasant meaning and was inspired by a James Ellroy novel based on a real murder case. She seems to be a bit on the short side - she is shorter than Luna and Alice. She is slightly taller than Clover.
In Virtue's Last Reward, Phi wears a white tank top over a short black dress that has a sky blue ruffle along the bottom. She also wears a long, sleeveless jacket resembling a lab coat, with the same sky blue color. She has a black beaded necklace that she wears over her shirt and large, shin-high black slouch boots.
A brooch is located on her left breast area, along with a bracelet on her left wrist. The brooch has a Latin phrase written on the back: "Elapsam semel occasionem non ipse potest Iuppiter reprehendere", which translates to: "Not even Jupiter can find a lost opportunity". This basically means that not even the Roman god Jupiter, the most powerful of gods, can turn back time to do something different.
In Zero Time Dilemma, Phi wears a boat-neck long-sleeved white shirt with the sleeves pulled back to her elbows. Her brooch is fixated on her left breast. She wears blue jean-type shorts that go up to her midriff and down to her upper thighs. It is also suggested that her undershirt is connected to her shorts, being a jumper. She also wears black combat boots and light blue-framed glasses. Her hair is flatter and she has orange eyeshadow in the corners of her gray/cyan eyes. She has orange eyebrows; Phi claims that this is because her natural hair color is red and she bleaches/dyes it white because she believes she wouldn't look good as a redhead, plus she wants to be unique. Her hair is slightly tinted pink/orange in light of this. Like the other participants, she has a black bracelet on her left wrist.
- "I'm kind of an unknown variable in this equation. You could think of me as a kind of... x-factor. It's kind of like the relationship between classical mechanics and modern physics. Strictly speaking, you can't combine velocities with (v1 + v2). (v1 + v2) / (1 + (v1 x v2) / c²) is the actual equation. Of course, the sort of velocities we encounter in day-to-day life don't come close to being c², which is the speed of light squared. That means that (1 + (v1 x v2) / c²) is usually going to evaluate to something pretty close to 1. Since that would mean dividing by 1, it's usually okay to just skip that step and use (v1 + v2). You see what I'm saying? In most situations it works, even if it isn't technically correct."
- — Phi in Another Time END, on her role using velocity-addition formula as a comparison
At the start of VLR, Phi is generally rather cold, methodical, bitter, and curt, but not necessarily callous or cruel. Blunt to a fault, her cool attitude can be off-putting and sometimes interpreted as rude, such as telling Alice to "spare her the bullshit". She can be demanding when she needs something, such as information from Dio, and she uses profanity when agitated. She is overly sarcastic at times as well. She is also not afraid to examine corpses for clues, showing bravery and courage, and perhaps hinting she is desensitized and has seen some morbid things even before the Nonary Game. She is also impatient and does not like it when people are not careful. Phi is very mysterious and she is very secretive about her past and rarely talks about it. She does not trust many of the people around her, except Sigma for the most part. If Sigma betrays her, she is especially bitter and mentions that she will make sure he regrets it.
In the beginning of VLR, Phi can interpreted as a rather selfish young woman who holds her life above others, willing to betray others to protect herself, although this aspect gradually changes throughout the game. She can also be interpreted as being deceitful and manipulative, as shown during Luna's route where she convinced K to ally by trapping Dio outside the AB Room, since picking betray would be worse for her, and giving K a hard time when he claimed that he picked ally due to a connection he felt with Phi. Also, when Sigma and Phi betray Tenmyouji during Clover's route, she tricks Sigma into having him take all the blame, causing Tenmyouji to get unfairly angry at Sigma, but maintaining Tenmyouji's trust for Phi. As the game continues, she has more compassionate and empathetic moments and begins to care about the other players (except Dio, who she perceives as an asshole), and wants them to escape alive, showing the comraderie of the players. An example of her change is when she is annoyed at Sigma sacrificing his life to save her in K END.
She tends to become close to Sigma, acting as his partner, and even hugs him when they both know they will be killed by the bombs. She also explains that she feels Sigma is important to her somehow. Phi being on Sigma's side may be because Sigma is her father, and they share a direct blood connection. It may also be because of repressed memories of the Decision Game still existing in the VLR timeline, because she and Sigma begin the Nonary Game together, and also because she was raised by a couple of old researchers and Sigma in VLR is elderly. At another point, she trusts K, possibly he is Sigma's clone and her half-brother.
Phi possesses a vast amount of intelligence, including on philosophical topics such as Schrödinger's Cat, Latin (her brooch inspired her), science and physics. When the players need to enter the Chromatic Doors, Phi is usually the one who will calculate the possible combinations for everyone else due to her agile mind. Without her keen intelligence, everyone in the Nonary Game would probably be dead much sooner. She can explain annihilation energy. She also knows about "alien hand syndrome".
Despite her attitude, Phi has some quirks. For example, despite her intelligence, she has a brainfart and says "take the piss out of a lime" when she meant "pass the time" and accidentally calls an asterix "agricola". Despite her braver nature, she screams when her wrist is sprayed. Despite being annoyed at Sigma's perviness, she offers to dress in a swimsuit for him to cheer him up in their final moments (which is made more disturbing because Sigma is her father, although both of them are unaware of this). In the elevator, Phi says she wishes she had a baby, and when Sigma asks her if she likes kids, Phi replies, "Yeah...I guess so", suggesting that she is willing to have a maternal side to her. In the infirmary, Phi may sing a little song, implying she likes music and singing. She also enjoys puns to an extent, since she often makes them with Sigma. Phi also seems to have a complex about her bust size, claiming that she is a C cup, then later, a D cup.
In Zero Time Dilemma, Phi returns, still sassy as ever. However, this time, she has the weight of the world on her shoulders and has an apocalypse to prevent. Phi's self-sacrificing attitude, which she obtained throughout VLR, shows and she is now willing to die in an incinerator for a 50/50 chance of saving Sigma's life, despite that there is a possibility they can both survive. If Sigma dies, Phi is furious at Diana for pulling the trigger, saying she didn't matter. If Phi is incinerated, she holds no resentment towards Diana and asks that she survives. Phi's selflessness in Zero Time Dilemma is an example of her character growth, as she had a lot of selfish moments in Virtue's Last Reward. She is also concerned about others' safety, warning Sigma not to press the button in the Healing Room and even suggests killing herself to prevent Radical-6 from spreading.
In Zero Time Dilemma, Sigma and Diana are trapped in the Underground Shelter in one of the alternate timelines of the Decision Game. With ten months of food to sustain themselves and Gab, the couple waits there in hopes that Akane Kurashiki, who had escaped the facility, will return to rescue them. However, after a month, Diana expresses doubt they will ever be rescued and begins to despair, but Sigma provides comfort for her and the two eventually build a romance that ultimately results in Diana becoming pregnant.
Nine months later on November 16th, 2029, Diana gives birth to twins. The first is a boy, whom the couple name Delta. The second is a girl who is named Phi in honor of the girl of the same name the two participated with in the Decision Game. Born with esper abilities, Delta was born a Mind Hacker and Phi was born a SHIFTer, due to the epigenetics and stress of their parents. However, with no food left in the facility, the couple decides to use an ancient alien technology in the Transporter Room, which recently regained power to be utilized, to send their children's atomic data through spacetime in hopes of giving them a better life. Before copying their data, Diana bestows her bluebird music box to her son, while she gives Phi's brooch to her daughter. She also writes their names on their feet so their new parents will know their names. What happens to Sigma, Diana, the original Phi and Delta, and Gab is unknown. It is possible they were rescued, but it is also possible the five of them starved to death.
As a result of their atomic data being sent through time, Phi and Delta were eventually "reconstructed" in 1904 in Germany. Ten months later, that reconstructed Phi was once again scanned into the machine. While it is not exactly known what happens to 1904 Phi, it is implied in the "Other Phi" file in Zero Time Dilemma that 1904 Phi eventually became a scientist who worked in an American lab.
In 2008, the ten-month-old Phi was once again reconstructed in an American lab and was adopted by two scientists working there, possibly implying 1904 Phi is the adoptive mother of 2008 Phi.
The Phi that was reconstructed in 2008 retained no memory of her true parents or her first cloning. Her only memento of her mother, whom she is told died shortly after her birth, is a brooch with the latin phrase: "Elapsam semel occasionem non ipse potest Iuppiter reprehendere", which translates to: "Not even Jupiter can find a lost opportunity". Phi spent a lot of time trying to figure out what her mother was trying to tell her.
Dcom experiment and Decision Game
On December 25, 2028, Phi was knocked out with the white gas that was used on everyone else. She had a consciousness swap from 2074. Phi then participated in the Mars Mission Test Site (Dcom) simulation in Nevada. Using Crash Keys' assets, they hacked the admin server and altered the original subject list and data to include Sigma, Phi, and Akane.
On December 26, 2028, Sigma attempts to tell everyone that six billion people will die, but is ignored when most of the others don't believe him and almost sent into confinement. Phi tells Sigma that they shouldn't mention the future to anyone. Sigma, Phi and Akane search the facility but can't find any signs of Radical-6. Sigma begins to suspect Akane may have lied to them.
On December 30, 2028, everyone meets again, but Sigma, Phi, and Akane reluctantly await the events of the next, unaware of what is to come.
On December 31, 2028, however, it turns out that the simulation was a trap and the Decision Game occurs. In the D-END: 1 route, Phi is injected with Radical-6 by Mira as revenge for setting the bomb in the decontamination room. Knowing what will occur in the near future, Phi asks Sigma to burn her body to keep the virus from spreading. Diana tazes Phi with a stun gun to knock her unconscious and vows to save both Sigma and Phi. Phi is presumably sent to a hospital, but from there, the virus spreads, leading to the events of Virtue's Last Reward.
After the virus got out, Phi survived the Radical-6 outbreak that spread throughout Earth. It is unknown how she survived since she was the source of it, but it is said that Radical-6 has a mortality rate of 75% so it's possible that Phi was one of the lucky 25%.
Later, Phi volunteered to participate in the AB Project orchestrated by Sigma and Akane Kurashiki in 2029 to change history. On April 13, 2029, Phi was already frozen in a Treatment Pod. Her body went to 2074, and her consciousness jumped forward to after the conclusion of the AB Project.
For 45 years, Phi was placed in cold sleep in a Treatment Pod, until reawakening in Rhizome 9 on January 25, 2074 with her last memories being from before December 25, 2028.
Virtue's Last Reward
When the game starts, she finds herself trapped inside an elevator-like room, along with Sigma. The two eventually escape the room after being introduced to a rabbit AI named Zero III. The pair find themselves in an abandoned warehouse alongside seven other people: Alice, Clover, Dio, K, Tenmyouji, Quark, and Luna. Their goal is to escape from the building. However, they find themselves enrolled in a game known as the Nonary Game: Ambidex Edition, which relies on a system called "Bracelet Points" ("BP"), which are won by cooperating with or betraying other players in AB Rooms. A player is allowed to leave the warehouse through the Number Nine Door only if they possess nine or more BP; however, if a player's BP reaches zero, they are killed by a lethal tubocurarine injection.
Throughout the Nonary Game's many branching timelines, Phi remains relatively close to Sigma.
In Luna's timeline, K claims that he felt a connection to Phi, and that he felt that they are both similar somehow, however Phi disagrees with this saying that she did not give him permission to have a connection. This may be because they are half siblings. Also, when Sigma fails to deactivate the antimatter bombs, Phi claims that he was very familiar to her.
Perhaps one of the creepiest moments in the game is when Phi displays symptoms of Radical-6 in Clover END. She merely stares at Sigma with a dead look in her eyes and body and does not respond to Sigma's questions. Later, Sigma discovers Phi slashed her throat with a scalpel.
Throughout the game, it is revealed that, like Sigma, Phi is an Esper and has the ability to send her conscious mind through alternate timelines, albeit not as skillfully as he can. She cannot freely choose to jump between timelines, nor can she completely retain her memories when she jumps as easily as he can.
For the first round of the AB Game, she and Sigma pair up with Alice and go to the Crew Quarters. After she tells Sigma about the Prisoner's Dilemma, he betrays Alice who picked ally, much to his surprise, as he remembered in another timeline, Alice picked betray and they had picked ally, with her stating that picking ally was a foolish choice.
For the next round of the AB Game, Phi is a Magenta Solo, and she goes with Sigma and Luna into the red door and heads into the Control Room. After escaping, she betrays Sigma and Luna in the AB Game, who ally, wanting revenge for an alternative timeline where she picked ally, but Sigma betrayed her. Sigma eventually remembers this and is able to convince Phi not to leave, partially due to her wanting to know the truth about the game, much to the relief of the others.
At the infirmary, Sigma remembers other timelines and remembers Dio owning the bombs. He tricks him into admitting it, Dio pulls out the detonator and has everyone move back, except for Tenmyouji who kicks him. This causes the detonator to move one meter away from Dio, putting it on countdown mode. Using the other timelines, Sigma and Phi are able to remember the bomb locations (except from Bomb 0, but Sigma successfully deduces a possible location) and passwords, deactivating the bombs with a minute to spare.
Phi along with Tenmyouji and Sigma head into room Q and learn some of the truth of the Nonary Game from a hologram of Akane Kurashiki. It is learned that Phi was recruited as a part of the AB Project due to her latent power in jumping between timelines.
AB Room: Past
Phi and Sigma jump back into the past, one hour before the start of the Nonary Game, to prevent Dio from killing Akane. By saving her, they altered the past, bringing a new future. Akane ties a key to Sigma around his ankle, just before he is forcibly pushed back into the future.
Phi END continued
Sigma and the group successfully escape through the Number Nine Door, leaving Dio handcuffed to a sink in the Infirmary. Upon leaving the facility, they find out from Tenmyouji that they were on the Moon and that the current date is January 25th, 2074. He also explains that Radical-6 caused 18 antimatter reactors to explode, which caused a nuclear winter. Luna reveals Phi was infected with Radical-6. The reason for this was to further speed up the development of Phi's SHIFT ability and send her consciousness to the past.
Sigma leads everyone to the B. Garden, where he unlocks the grave. A treatment pod appears, presumably holding Akane. However, it must defrost for a while before it can be opened. While they wait, K explains about everyone's importance in the Nonary Game. When K finishes, the pod opens, revealing a Sigma clone. Everyone is confused who he is, saying that they've never seen anyone like him before. Sigma tries to get everyone to stop playing around, but no one seems to be joking. Panicking, Sigma finds a small pond in the garden and looks at his reflection. Shocked, Sigma discovers his 22-year old mind in an older version of himself. Suddenly, K sheds his armor showing that, in this timeline, K was actually Akane.
Akane explains that this was all a part of the AB Plan and that his current young mind switched places with his older mind. Akane explains that Sigma was there to develop his time jumping abilities along with Phi. With his training complete, Akane tells Sigma that it is his time to return to his past body. Akane then proceeds to attack Phi with the knife she recovered earlier from Dio. Sigma throws himself in front of Phi to protect her and is seemingly stabbed, but Akane merely hits him with the handle of the blade. Regardless, Sigma's and Phi's minds return to the past to April 13th, 2029.
Another Time END
? meets Phi in the Director's Office, after she fails to keep the virus contained. Sigma told Phi to show Kyle/? a hologram of Sigma talking. Phi is asked by ? about her involvement at the Mars Mission Test Site, but she does not tell him anything, because if ? knows why the mission failed, the possibility of getting to Point E (Radical-6 doesn't escape from the test site) disappears. It is also revealed her consciousness went back to the past along with Sigma's when Akane attacked her. She then says that she is sort of an X factor in all of this. She is suspicious of how ? knows so much about the events that occurred, despite being unconscious at the time. This causes ? to leave to go find Akane.
Zero Time Dilemma
Phi, SHIFTing her consciousness from the events and timeline of Virtue's Last Reward, participates in the Mars Mission Test Site simulation in order to stop the spread of Radical-6 from the site.
During the Mars Mission Test, she approached one of the women participating in the experiment with her, Diana. Out of the blue, she asked Diana if she could hug her. As she embraced her, something about Diana's scent seemed familiar to her.
D-END: 1 (Circle Of Fate/A Rabbit In Your Future)
After escaping the Manufacturing area, D-Team realizes that they can escape the facility by bombing a hole through the Decontamination Room. Utilizing a bomb from Manufacturing, they decide to follow through with their plan. However, after placing the bomb and running back to the Lounge, Zero appears on the monitor and informs them that Q-Team is on the other side of the door in the Decontamination Room, and that they will die if they do nothing. When they head back in, they find a protective suit, and that the showers containing hydroflouric acid have been turned on. Diana and Phi run, but Sigma stays behind. He fails to stop the bomb, and as such, is unable to escape the blast and loses his right eye as well as both of his arms in the process. Phi and Diana manage to bandage him up and the three use the newly created hole into the elevator shaft where they find Q-Team dead.
As Phi checks Mira, it turns out that she was still barely alive and Mira injects Phi with a vial she received from the Biolab containing Radical-6 before she dies. Phi realizes that she is the reason why Radical-6 was introduced to the world. Knowing that going to the surface will cause the virus to spread, Phi volunteers to kill herself and burn her corpse in order to prevent this, however, Diana refuses, tazes Phi with a stun gun, and forces the central elevator to return to the surface.
At some point, Phi is presumably hospitalized (away from Sigma and Diana who also manage to survive the Radical-6 outbreak) and the virus begins spreading there. It is never explained how Phi survived the Radical-6 outbreak since she was the source of it, but it is said that Radical-6 has a mortality rate of 75% so it's possible that Phi was one of the lucky 25%. Another possibility is that the major espers (Sigma, Phi, Diana, Junpei, Akane) were immunized in such a way that the virus wouldn't affect them, but could still kill nearby others.
In the end, with the series of events that occurred in this route, this leads to the start of the events of Virtue's Last Reward. As such, Phi four months after the outbreak, Phi later meets with Akane (technically, Akane's transported self who may be considered a clone) and Crash Keys, and Phi willingly goes into cold sleep so she can participate in the Nonary Game: Ambidex Edition.
D-END: 2 (The Hope Of Two/A Silver Lining)
During the "Fire" decision game, Diana cannot bring herself to risk killing Sigma and ultimately allows time to run out without her pulling the trigger. This causes the incineration process to start and Phi sacrifices herself, saying that this was the best option as her only desire was to have Diana and Sigma live on. Phi's last words are simply telling Diana that there is something familiar about her and that she loves her. The incinerator starts and in mere minutes, nothing is left in the incineration chamber but ashes and Phi's brooch.
After Diana and Sigma complete the Transporter Room's puzzles, they find themselves stuck in the Underground Shelter as Akane had used the X-Door to escape. This eventually leads to the events that take place in the Background section.
Force Quit: D
With all three teams spreading the votes during the first Decision Game as well as not pressing the yellow button in the Decontamination Room, D-Team, like the others teams, eventually awaken in the Lounge alive, but still by themselves. However, the mysterious Force Quit Box, which was previously closed, is now open. Inside, the screen displays a message asking for "Mother's Mementoes". If the D-END: 2 Route is completed, Diana realizes that the mementos refer to the gifts she gave to her children in that route. After Diana suddenly embraces Phi, both Sigma and Phi, through morphogenetic resonance, recall that past as well, revealing that Phi is a reconstructed version of their daughter. The family tearfully embrace, now fully aware of their reunion in another history.
CQD-END: 2 (Pay-off 2/The Final Decision)
In the True ending route, Phi discovers the truth of the Decision Game. After learning that Delta is her brother, she angrily shouts "FUCK YOU!" at him and kicks him in the head.
Phi and the rest of the Decision Game participants decide to SHIFT to the alternate history where they won the coin toss with all memories of the events of the Decision Game still in their minds. Phi survives the ordeal, though it is not known what became of her after the final decision, such as whether or not she chooses to pursue the religious fanatic.
Virtue's Last Reward
- "I'm plenty friendly."
- "Shut up! Just back off, grandpa!" (to Sigma)
- "You stay away from me, all right!? Don't even THINK about doing anything! If any part of you touches me, even by accident, I WILL BREAK IT OFF! WE CLEAR!?" (to Sigma after he asks her if she wants to make a baby with him)
- "I KNEW it! You sick bastard!" (after Sigma claims he's not hoping to get his face sandwiched between a girl's bare thighs)
- "I don't want to die here any more than you. Let's go."
- "Well, I'm not Superman, that's for sure. And I'm not Batman, or Spiderman, or Aquaman, or a merman, or a wolfman. I'm not a brahman, or common, or ramen. I'm not a caiman either, so you don't really need to worry about anything. My name is Phi. I guess you could say... I am no man." (after leaving the Elevator)
- Sigma: "I'm Sigma.. And this bundle of laughs is Phi. Good to meet you all, I guess."
Phi: "Say. That. Again."
Sigma: "And this malnourished harpy is Phi. Better?"
- "Oh my God! There's dihydrogen monoxide coming out of that faucet!"
- "La-La-La! Lu-Lu-Lu! Look at all the cats today! La-La-La! Lu-Lu-Lu! Timeeee gooooooes byyyyyyy! La-La-La! Lu-Lu-Lu! Whenever I think of you, my heart is set on fire! Nothing can come between me and you!"
- "UGH! Were you even paying attention?"
- "Spare me the bullshit! This isn't time for keeping secrets!" (to Alice)
- "Guh... What'd I do to deserve this asshole?" (being paired with Dio)
- "That logic is flawed and more than slightly disturbing. Unfortunately, I don't really have a counterargument, so center door it is." (to Dio)
- "Hurry! What the hell are you waiting for?! Choose betray!"
- "If our BP drops below 1... we... we... we DIE!"
- "That's no excuse. And where do you get off telling me I shouldn't have picked "betray"? Did you even think that through?! What, I was supposed to pick "ally"? If I'd done that, I'd be dead right now!" (arguing with Tenmyouji)
- "Me? Talk to Clover? I'd have about as much luck talking to a potato right now."
- "Sigma! What the hell are you thinking?! Get back here! No... You don't mean... You're going to find Luna?! Goddamnit Sigma! Think about what you're doing! Sigma! Listen to me! You can't do this! SIGMAAAAAAAA!" (Luna END)
- "I don't want... to live if it means... being in debt... to you..." (to Sigma in K END)
- "...SHIT." (when Clover escapes through the Number Nine Door and leaves her behind)
- "DON'T SCREW WITH US!" (to Zero III)
- "The tortoise won because he kept going even when it looked hopeless. I think we should do the same. We've got plenty of time, after all. We'll give the dead the closest thing to a funeral we can manage... And when that's done, we'll start looking. Even if I never leave this place, I'll figure out why we were here. I swear it."
- "Don't worry. We'll figure it out, I promise. You know what they say: Swimsuits never quit." (trying to cheer Sigma up when they know they might die)
- "Our time's up. This is it. Before... well, before it ends... I wanted to tell you thanks. You know we're about to die, but you still stuck with me. So... thank you, Sigma. Goodbye..." (if the player fails to deactivate a bomb)
- "You think I don't KNOW THAT?! What other choice do we have?! Every minute we spend wrestling this PRICK is a minute we don't have to deal with THOSE BOMBS! We don't have time for this!"
- "Oh, for God's sake... Luna! SHUT HIM UP!" (regarding Dio)
- "You still haven't answered my question. I'm going to ask you one more time. What is the password for the number zero bomb? ...Now. Tell me. What's. THE. PASSWORD?"
- "Well played, Sigma. I guess a promise means a lot to you. Why did you do it? Nothing to say? I guess I misjudged you. I thought you were better than this. That was not a smart move, Sigma. I won't forget this. I'll make sure you pay, even if it's the last thing I do. Elapsam semel occasionem non ipse potest Iuppiter reprehendere."
- "Then where the hell did you learn all this stuff!? I just listened to you tell me a bunch of things you shouldn't have known about! You were sleeping in the pod in the garden. You just woke up! So how can you know all this? You know my past! Sigma's past!" (to ?)
Zero Time Dilemma
- "There's no point. We wouldn't hear a drunk toga party at full volume on the other side."
- "Sigma, why don't you try dying once?"
- Sigma: "When did you get so high and mighty?"
Phi: "Since birth."
- Sigma: "What the hell are you doing in there?"
Phi: "Cutting my next album. What do you think I'm doing?! I'm locked in here!"
- "You're the one flailing and freaking out here!" (being told to stay calm by Sigma)
- "I'd like to avoid the worst sunburn of my life in here!" (trapped in incinerator)
- "Diana and Sigma are over there... Damn! Why am I here... But it's better that I'm the only one who got locked in. Diana... Sigma... I'm counting on you guys." (trapped in incinerator)
- "So this is the spot where the flames will come out from.... I wonder how powerful this is. Maybe there's something I can hide in or behind if the incinerator starts up... ...Yeah, I didn't think so. I know, maybe if I stuff the trash into the furnace... Dammit, it stinks to high heaven! I need to stop firing myself up or else I really will be... ...Stay calm, Phi." (searching the incinerator)
- "Call HR, this is sexual harassment." (to Sigma when he asks her how much she weighs)
- "How dare you not even consider everyone else's feelings, Sigma! What if the shot is a live bullet?! Do you really want Diana to end up blowing your head off with her own hands?!" (to Sigma, when he suggests Diana risk his life to save Phi's)
- "Why?! Why did you do it?! You murderer! Murderer! I wasn't... I didn't matter at all! I didn't...! I didn't...! So why... why did you..." (Phi furious at Diana for killing Sigma)
- "That's all I needed to hear from you, Sigma. Thank you. And Diana, you can't blame yourself. No matter what. You made the right decision. It's weird, but... I feel like we'll see each other again. So I'm not going to say good-bye. I want the two of you... to keep on living. I love you..." (final words before being incinerated)
- "I didn't ask for any help..." (to Sigma)
- "It's just not that easy to see a person's true self."
- "Then kill me! Kill me and burn my remains! Now! There's no other way... That's the only way to keep the virus from spreading... Come on! Hurry! Six billion lives are on the line!"
- "What?! No... Diana, you're..." (realizing Diana is her mother)
- "ARGHHHHHHHHHHHHHHHHHHHHHHHH! FUCK YOU, YOU GODDAMN OLD MAN!" (kicking Delta)
- "Humanity's going to die out? Screw that!"
- When Phi is thinking hard about something, such as figuring out the answer to a puzzle, she has a tendency to put her thumb and index finger on her chin and stare at the floor, lost in her train of thought.
- Her catchphrase is "It's just a possibility".
- At one point during the earlier parts of Virtue's Last Reward, Phi mentions she does not believe in the existence of ghosts.
- The reason why Phi's coat is so large is to subconsciously make the player perceive her as "immature" as if she has not grown into her own clothing, and foreshadows that she has a bit of an immature and childish personality at times. It also vaguely resembles a lab coat which could reference Phi's interest in science.
- With a total of seven, Phi goes through the most escape rooms with Sigma in Virtue's Last Reward. Additionally, paired up with him thrice (Round 1 and two of the possible Round 3s), she is the only character whom Sigma is paired up with more than once.
- Like Sigma and Delta, Phi's name is a Greek alphabet derivative -- it came from being named after the version of her that was in a history where she survived -- she was named after herself (therefore, like many things in the series, such as the motivations of Zero in both 999 and ZTD, Phi's naming invokes the bootstrap paradox).
- In VLR, the only time when Phi's time jumping abilities are present (besides Phi END) is in Dio END. In this ending, Phi knows that Dio is a Free the Soul member and that he planted the bombs; this means she had probably seen the Sigma or Alice END by that point, even though the Dio END is needed before Sigma can see either of those endings.
- Phi has the all-time highest BP total in the game after the 5th round of the AB Game during Phi END, with 15 BP.
- If Sigma fails to deactivate the bombs, Phi shares an intimate moment with him.
- This scene is made even more tragic with Zero Time Dilemma, as it's a father and daughter sharing their final moments together in a hug, without them knowing the truth of their relationship.
- Before Zero Time Dilemma was released, Uchikoshi said that Phi and Sigma would not be a couple, but couldn't answer why due to spoilers. In the gap of years between the two games, fans made a lot of romantic Sigma-Phi relationship pairing material, which is now made awkward.
- In Virtue's Last Reward, Sigma jokes about making a baby with Phi, to which she punches him. The irony is that Phi is his "baby".
- It is implied by the cinematic files of Zero Time Dilemma that Phi is her own adoptive mother as the Phi who was sent back to 1904 and arrived in Germany was said to be working as a scientist at the American facility that the Transporter was being hosted in when the 'current' version of Phi was sent into 2008.
- It is said that 1904 Phi is a centenarian (someone who lives beyond 100 years). This is possible considering Delta is 124 years old, and he seems to age slower. It would make sense if Phi aged slower too. It's also possible that 1904 Phi is still alive by the time of 999 and Zero Time Dilemma.
- Due to the above, it is possible 2008 Phi will become a centenarian or potentially even have an age in the 200s/300s/etc.
- Phi may be a bit of a food aficionado. On Luna's route in Virtue's Last Reward, she investigates the Pantry with Dio and K. She later takes Sigma there while searching for Quark and she tells him she sampled the paella, nasi goreng, schnitzel, yukgaejang, borscht, and tom kha gai, as well as the chef's pasta and twice-cooked pork. She suggests that she did all of this so as to convince Dio that she was absent-minded, which came in handy when she outsped Dio at that time. In the Healing Room in Zero Time Dilemma, if Diana examines the black water in the tank in the sky room, Phi expresses that she enjoys spaghetti with squid ink.
- In Virtue's Last Reward, she claims to be a "really friendly drunk". In the Lounge escape room on Easy mode, examine the bottles that don't go in the inventory.
- It is a mystery why Phi wears glasses in Zero Time Dilemma and not Virtue's Last Reward. Perhaps she lost her glasses in the early months of 2029 during the Radical-6 apocalypse, such as when she was being hospitalized. It is also possible she wears glasses purely for fashion reasons, as she is dedicated enough to bleach her hair because she feels it wouldn't look good from a fashion perspective.
- When Phi and Delta are born in D-END: 2, her icon changes from dead to alive on the status screen.
- Phi's doll type in the status screen is known as an "articulated paper doll" or a "jointed paper doll", perhaps referencing how easily paper can be incinerated, as Phi is put in an incinerator in the game. For unexplained reasons, she seems to have elf ears, a possible reference to her being abnormal as she and Delta are superhumans.
- Phi's Greek letter is also used as symbol of the golden ratio, which itself is the sum of never-ending cycle, just like Phi herself. The golden ratio is also the first order of metallic ratios that is usually denoted with the Greek letter Sigma, this is possibly a hint to her relationship with Sigma. The golden ratio curve is also featured on the cover of ZTD's artbook, which also features Phi's mother Diana.
- In Zero Time Dilemma, Phi has sectoral heterochromia, with the bottom of her irises being cyan while her overall eye color is gray. Her mother also has this.
- Phi's jump kick at Delta is a throwback to when she kicked Dio in VLR. Oddly enough, when she kicked Delta, Phi is able to jump very high and proper her body in a superhuman way, despite that she isn't located on the Moon. It is unknown if this is due to Phi possessing superhuman jumping abilities due to the nature of her birth, or an unintentional developer goof/oversight.
- Phi is the only main character in Zero Time Dilemma who has never directly killed another character (if the fact that Sigma, as Zero Sr., killed many people via the game he created and engineered is taken into account).
- Phi's X-Passes are Dear, Twin, Red, Future and Time.
- Dear - Not as direct as the other X-Passes, this one seems to refer to the mother-child relationship that Phi and Diana have.
- Twin - How she and Delta are twins.
- Red - Her true hair color.
- Future / Time - Phi's existence as a time paradox.