Utsuho Reiuji is one of Satori's pets, a Hell Raven who has lived in the underground world since before it was separated from Hell. Her job is to regulate the flames of the Hell of Blazing Fires. she was told by a voice (presumably Kanako's) that she could swallow the god, Yatagarasu, that was hidden in the flames to gain a power that would fulfill the wishes of both the worlds below and above the surface. This power was nuclear fusion. Utsuho misunderstood what the voice had told her, and decided that, using these powers, she would take over Gensokyo. Her friend, Orin, became worried about Utsuho, and drove evil spirits to the surface to cause an incident among the strong youkai above ground, in hope that they would come down to do something about it and, when they got there, defeat Utsuho and bring her back to her former self. What came, however, was not a strong youkai, but a strong human.
- Ground Melt: Utsuho fires a laser at the ground, causing it to melt and deal damage to opponents on the ground.
- Hell Geyser: Utsuho slams her cannon on the ground, causing a lance of nuclear energy to jut up from the earth.
- Radiant Blade: Utsuho charges forward, surrounded by a yellow glow. Once her charge has ended naturally or she contacts an opponent, she then immediately lunges back and fires a 3-hit blast with her cannon.
- Flare Up: Utsuho summons 2 plasma balls from the ground around her, which spiral upwards.
- Rocket Dive: Utsuho propels herself forward using nuclear fusion and attacks.
- Melting Pummel Kick: Utsuho lunges forward with her left foot raised, surrounded in nuclear flames. If she touches the enemy, she then slams them down and proceeds to roast them with aforementioned flames, kicking them aside with her concrete foot afterward.
- Retro Atomic Model: An energy ball spins and follows Okuu. The ball itself can be used as a shield or a weapon.
- Vengeful Nuclear Spirits: Utsuho summons a floating radiation warning sign with the Light button. Upon using the hard button, the sign then fires a series of bullets in the opposite direction of wherever Utsuho is relative to the sign.
- Shooting Star: Utsuho flies slightly upwards as she summons pairs of plasma balls above and below herself, which arc outwards after a short period of time.
- Break Sun: Utsuho creates a sun-like object above her head, and pulses light particles at the enemy. Holding the button down will make the attack stronger.
- Shooting Sun: Utsuho conjures a small fusion ball over her head before tossing it in front of her. Holding down the buttons makes the ball float higher over Utsuho's head, causing a farther shot when released.
- Hell Wave Cannon: Utsuho conjures four balls of very dense nuclear energy in front of her. Letting go of the button causes her to hurl all four of them forward. Holding the button causes all four balls to gradually spread out and change the angle of fire. Holding the button for the entire duration causes the orbs to instead fire lasers that go all the way across the screen.
- Fixed Star: Utsuho throws a ring of nuclear energy at the opponent. The energy ring moves backwards after a while, and hits the enemy a second time.
- Geothermal Sign “Nuclear Blaze Geyser”: Utsuho channels nuclear energy into the ground, releasing a series of powerful energy columns that knock her opponent away from her with great force.
- Giga Flare: Utsusho shoots a beam at the enemy. If it hits the enemy, the enemy will be trapped in a nuclear sign, which will eventually explode.
- Battle Intro: She flies in and says "Witness the power of nuclear fusion!"
- Taunt: She stands in place, with a question mark above her head in a thinking pose and says "Unyu?".
- Victory Pose: She says “Nobody can withstand the ultimate energy!” and raises her cannon while Rin Kaenbyou dances behind her.
Compared to the Sun, you are but a puny existence. But I won't show any sympathy!
This still isn't enough to stop this surging feeling! The nuclear reactions within me force me to rage even more!
Lord Yatagarasu, the Black Sun. Thank you for giving me your power.
My ultimate nuclear energy melts up everything completely! How would you go about taking me down then?
Vs. Self: The sun continues to burn today.
Vs. Reimu and Sanae: Hey, it's a shrine maiden. I can't tell you shrine maidens apart from one another.
Vs. Marisa, Mokou, Gun Users and Shantae: You couldn't even roast a bird with that firepower.
Vs. Sakuya: Techniques that are only fancy tricks are no match for overwhelming power!
Vs. Patchouli: You're relying on such pitifully boring magic aren't you? From now on it's nuclear power! The nuclear age!
Vs. Sword users: With nuclear fusion you could even practice metallurgy and make a great business of it!
Vs. Hsein Ko, Murasa and Yuyoko: I'm someone who's become used to revengeful spirits, so normal spirits are refreshing.
Vs. Yukari and Tessa: Eh? There are many people outside who terribly misunderstand nuclear energy and disapprove of its use? Even though it's so useful...
Vs. Cirno, Rumia, Mystia and Wriggle: Wait, what? You didn't get blasted to smithereens. Was the output too low...?
Vs. Suika and Yuugi: It's okay, the Underground City can prosper. After all, the only weakness the underground had was that it didn't have a sun!
Vs. Kaguya and Reisen: The sun will drive back the moon!
Vs. Aya and Frank West: I'm sorry, I hardly ever read newspapers.
Vs. Felicia: Oh, my friend is a cat girl! You should meet her!
Vs. M. Bison: Your pyscho power is only half as powerful as my Nuclear energy!
Vs. Megaman, Bass and Zero: I'll show you how to use that arm cannon!
Vs. Ryu, Chun Li, Guile, Sakura, Juri, Akuma, Morrigan, Meiling, Dan, Ken and Cammy: You're always trying to close in on me. Are you trying to burn yourself to death?
Vs. Asura: Jeez, even melting your arms off didn't stop you. Well, doesn't matter. I couldn't let you destroy my reactor.
Vs. Demitri, Remilia and Flandre: You ain't conquering my sun!
Vs. Jon Talbain: I have made my own miniature sun, so your powers are useless.
Vs. Tron, Dr. Wily, Nitori and Alice: Your toys were bound to incinerate.
Vs. Wesker, Gene, Amaterasu and Hina: A god? I got my powers from eating one, punk!
Vs. Captain Commando and Viewtiful Joe: I'm the bad guy? Okay, maybe that one time, but I'm just trying to create accessible energy!
Vs. Ruby Heart: I don't need no stinking pirate destroying my reactor!
Vs. Hiryu: So much for your super ninja speed.
Vs. Batsu and Jin: You aren't hot blooded enough to handle the Yatagarasu!
Vs. Shikieki and Komachi: I haven't received enough damned souls in the blazing hell lately.
Vs. Iku: The waters in your kingdom should keep the reactor cool enough.
Vs. Keine: Once this reactor works, you'll have more to teach in your class.
Vs. Ichirin, Byakuren, Seiga, Futo, Miko and Iesua: I don't need religion. I already swallowed a god.
Vs. Koishi: Please keep this a secret from Satori-sama.
Vs. Mamizou, Momiji and Yuuka: I should have known I would butt heads with environmentalists eventually.
Vs. Mima and Shinki: Maybe I should throw you into the blazing hell myself.
Vs. Tenshi: So you're the perpetrator who inserted the keystone. It looks like the keystone was working effectively, the Lord of the land that it is.
Vs. Satori: Uh oh. Uh, don't worry, Satori-Sama! I'm not up to anything!
Vs. Firebrand: If you're a Red Arremer, then I'm a nuclear-fusion-brand...thing...bobble...Just shut up! I'm not stupid!
Vs. Medicine: I think the radiation made me immune to poison.
Vs. Anakaris: Ooh. You'll be a good fuel source for my nuclear reactor.
Vs. Yumemi: Oh, so your little maid there is Nuclear powered, eh?
Vs. Amingo: I hope you don't get radiation poisoning.
Vs. Nue: Oh. You got out of the underworld?
Vs. Sonson: Don't even think about coming near my reactor with that staff.
Vs. Kogasa: I could really use you to shield myself for future experiments in nuclear fusion.
Vs. Spencer: How do you expect to fight me when your arm doesn't even have a nuclear reactor?
Vs. Kasen: Your arm doesn’t even have a nuclear reactor. You lost before we even fought.
Vs. Seija: Maybe I should throw you into the blazing hell myself.
Vs. Nick: Perhaps you can help fix my generator.
Vs. Nero: Maybe I should use a motorcycle handle for my nuclear reactor.
(Utsuho returns to the Hell of Blazing Fires and greets Rin Kaenbyou.)
Utsuho: I'm back, Orin!
Rin: Welcome back, Okuu! Congradulations on defeating Fafnir!
Utsuho: Thanks! Hey, I just wanna say, I made some new friends and they're coming over!
Rin: Oh, how exciting!
(Various Capcom monsters enter. Among them include Nemesis, Firebrand, The Yellow Devil, Hauzer, Bishamon, Yami and Adam the Clown. Rin looks a bit scared.)
Rin: Uh....These are your friends....?
Utsuho: Sure are! Something wrong, Orin? You look a bit nervous....Rin: Uh, nevermind! I'll go inform Satori-Sama!