Formerly an ordinary human, Fujiwara no Mokou became an immortal being after drinking the Hourai Elixir roughly 1300 years ago. Now she is unable to die, though she can still feel the pain of injuries. Due to her longevity, Mokou has garnered much experience and is able to withstand great amounts of pain. Mokou has a long running history of hatred for Kaguya ever since the moon princess humiliated Mokou's father by turning down his marriage proposal after she caused him to fail her trial of the Impossible Requests. Even though it has been over a thousand years since that happened, she continues to detest Kaguya, knowing full well that she can never get her revenge--nor can Kaguya ever put a permanent end to her. When not fighting with Kaguya though, she aids the nearby villagers by exterminating youkai and will even guide them safely to Eientei for medical treatment. She is a loner by nature and chooses not to socialize with humans or youkai and has a dubious personality that can easily switch from friendly to threatening and back again, but her actions seem to indicate she may be a good person.
- Hollow Giant Woo: Mokou shoots a small flaming telekinetic ball which explodes and burns enemies on impact.
- Exploding Pillar: Mokou erupts into a pillar of flames and after a short delay, reappears. This is a melee attack that leaves Mokou invulnerable from after the initial startup until after she reappears.
- Jump Flame: Mokou jumps up and blows up the area beneath her in a cone. At the peak of her jump, she temporarily sprouts fiery wings which she can use to "descend" slowly. Jumping, dashing, landing or pressing S will cancel the wings.
- Dive Kick: Mokou kicks downward and drags opponent with her
- Candle Bomb: Mokou flips backward and tosses out 5 explosive candles (causes wall slam). The opponent can only be hit once by this attack.
- Phoenix Rekka: Mokou slashes the opponent with flaming claws up to 3 times consecutively. She can trigger the second and third slashes by pressing an attack button again after the first slash.
- 1st time: Moves forward and slashes in front of her (a little bit angled downwards).
- 2nd time: Slashes upwards. (Lifts the opponent).
- 3rd time: Jumps up and slashes upwards. (Lifts opponent)
- Hourai "South Wind, Clear Sky -Fujiyama Volcano": Mokou focuses her energy and releases it in a fiery supernova.
- Forgiveness "Honest Man's Death”: Mokou unleashes a flame barrage against the opponent.
- Possessed by Phoenix: Mokou will stomp on the ground and if the opponent get hit, they will get launched in the air. Mokou then turns into a Phoenix and flies at the enemy.
- Battle Intro: Mokou comes out of fire and says “Fair Warning, I’m a human oven.”
- Taunt: She creates fire in her hand and says “Piece of Cake!”
- Victory Pose: She says “You were pretty good.” She then creates a phoenix image behind her.
The day will come when you'll be dyed in red.
Would you like to try dying once?
All you half-dead people will be scattered away with a flap of this phoenix's wings!
My time is unlimited. That's why I must treasure this limited time.
Vs. Self: At this point, nothing can scare m- Wah, that's me!!
Vs. Reimu: Now that you mention it, I did some asking around over at Eientei. Seems like you're about to get dragged into some troublesome, nightmarish job.
Vs. Marisa: Immortality is lonely and inescapable.
Vs. Sakuya: Just what do you think you are, some kind of time lord or something?
Vs. Keine: Thanks, Keine. However, I think I can handle myself with Youkai.
Vs. Kaguya: You're really getting under my skin, Kaguya! You'll never win against me! Never, ever!
Vs. Reisen: The Lunarian bunch again? Give me a break. Should I take one of my lives and attack that place?
Vs. Nitori: I'll evaporate every last drop of moisture from you.
Vs. Miko: You're immortal too...?
Vs. Futo: At least you look pretty immortal to me.
Vs. Kokoro: Your face isn't smiling, you know? You're scary.
Vs. Mamizou: That tail looks like it'd burn up nicely.
Vs. Koishi: I always thought the Underground youkai were all a bunch of oddballs.
Vs. Ichirin: If monks could actually save people, this world would've already become paradise.
Vs. Byakuren: Well? Aren't you gonna read a sutra for my death's sake?
Vs. Cirno: So a person with control over fire defeats a person with power over ice? No surprise there.
Vs. Wesker and M. Bison: You want the elixir of Immortality? You’ll have to get through me first!
Vs. some Youkai characters, Amingo and Darkstalkers characters: Eat my flames, Youkai.
Vs. Chun Li and Juri: So someone did something to your father and you want revenge? I have gone through that, so you have my sympathy.
Vs. Hsien-Ko, Chris, Jill and Saki: Guess we know who the best Youkai hunter is.
Vs. Vergil: Now you’re REALLY playing with fire.
Vs. Phoenix Wright: Only one Phoenix was meant to prevail today.
Vs. Arthur: Instead of fighting me, you should go and rescue your princess. It's not polite to keep a lady waiting.
Vs. Komachi: Why exactly is a shinigami harassing an immortal when you know I can't die?
Vs. Sanae: So this is how the other miko fights....
Vs. Remilia, Yukari and Tenshi: Proud and noble, huh? Wipe that smug expression off your face, you're just pissing me off.
Vs. Murasa, Yuyuko and Youmu: I guess even immortals have to put up with ghosts.
Vs. Batsu: Hah! That's the spirit! Show me more of that fire!
Vs. Ryu and Akuma: Close, but my flame is still stronger.
Vs. Amaterasu: I ask of you: bless me just as the moon blessed my foe.
Vs. Megaman: I can't take your whole peace talk seriously when you're packing that much fire power.
Vs. Utsuho: My flames can even outmatch your little science project.
Vs. Roll: If you don't have the backbone to fight, why bother showing up at all?
Vs. BB Hood: How's that for firepower, you trigger happy little psycho?
Vs. Zero and Hayato: Never knew swords could pack this much heat.
Vs. Chris and Jill: You don't need to worry. I can handle whatever kind of abomination comes my way.
Vs. Hiryu, Viewtiful Joe and Captain Commando: You claim to fight for justice? I can dig that.
Vs. Ruby: Sorry for burning down your ship.
Vs. Asura: You almost destroyed the moon? Let's be friends.
Vs. Gene: I should incinerate that arm of yours for spanking me so many times!
Vs. Jin: Looks like your robot overheated a little.
Vs. Dr. Wily: Not much of an army when I can melt it all in seconds.
Vs. Shantae: Do not think your fire scares me, Genie. I've seen embers scarier than you.
Vs. Cammy: Careful. You don't wanna charge into a wildfire.
Vs. Yuugi: I hate fighting drinkers.
Vs. Tessa: Not sure there's really any way to explain how my powers, or even Gensokyo itself, works.
Vs. Satori: Sorry. All I'm thinking of right now is how to burn you to a crisp.
Vs. Firebrand: I have little tolerance for demons... much less inferior ones like you.
Vs. Medicine: I'll burn all your poisons out of existence.
Vs. Yumemi: Don't look at my flames to closely.
Vs. Sonson: I drank an elixir to gain my immortality, but heading to the underworld and erasing your name from the book of the dead sounds way more badass in comparison.
Vs. Kogasa: Careful. Umbrellas burn easily.
Vs. Spencer: Careful. Umbrellas burn easily.
Vs. Hina: Youkai, God, doesn't matter. They all burn the same.
Vs. Masamune: Bet your rival couldn't do that, huh?
Vs. Kasen: I see. Hermits gain longevity by fighting off shinigami.
Vs. Dan: Well, that didn't take too long.
Vs. Ken: THIS is how you use fire, buddy. Your punch is remedial in comparison.
Vs. Nick: Zombies? Nothing like a little wildfire to reduce their numbers.
Vs. Seiga: You take your immortality for granted. That is why you lost.
Vs. Nero: Now that is a kick ass sword.
(Kaguya and Mokou are about to confront each other.)
Mokou: Kaguya! We meet again!
Kaguya: *Sigh* You want to fight me again?
Mokou: Yes, but this time I got a person to help me!
Kaguya: Funny you should say that. So do I!
(Their allies are Chun Li for Mokou and Juri for Kaguya.)
Chun LI: This is it, Juri! I’m going to bring you in today!
Juri: Keep yapping away, police girl. You won’t be laughing once I plant my foot in your back.
Mokou: Let’s go, Kaguya!Kaguya: Don’t hold back!