The user can use their own rear to help them in combat, by using them with or without mundane, supernatural, bionic enhancement, users can use on their rear anatomy of the body and their function from external and internal structures for anything needed be it for ballast, shields, weapons, etc.
Busuzima (Blood Roar) who sits on peoples faces and FARTS on them!
Earthquake (Samurai Shodown)
Wan-Fu (Samurai Shodown)
Cham Cham (Samurai Shodown)
Cassandra Alexandra (Soul Calibur Series)
Sophitia Alexandra (Soul Calibur Series)
Voldo (Soul Calibur Series)
The Succubus (Disgaea)
Amy Rose (Sonic the Fighters game)
Lopunny (Pokémon Battle Revolution)
Various Fighters (Dead or Alive Series)
Fiona Mayfield (Arcana Heart)
Shun Di (Virtua Fighter)
Bridget (Guilty Gear)
Various Fighters (Pretty Fighter)
Watson (Battle Fantasia)
Various Fighters (Secret of the Eight Stones)
Neemon (Digimon Rumble Arena 2)
Jessica (Dragon Quest VIII)
Cindy (Final Fantasy X)
Makoto Nanaya (BlazBlue)
Platinum the Trinity (BlazBlue)
Natalia Glinka (Vanguard Princess)
Kitana (Mortal Kombat 9)
Kim (Scott Pilgrim vs. the World the game)
Lucifer (Umineko: Golden Fantasia)
Beatrice (Umineko: Golden Fantasia)
Marge (The Simpsons beat-em up game)
Juliet (Lollipop Chainsaw)
Valkyrie (Project X Zone)
The Amazon (Dragon's Crown)
The Sorceress (Dragon's Crown)
Sohma (Ar tonelico Qoga: Knell of Ar Ciel)
The Lagombi (Monster Hunter 3)
Twerkies, Twergulls and Twerkpeas (Miitopia)
Miyuki (Fight Fever)
The Drop-bear (Australian Cryptid)
Astro (Astro Boy) using his butt guns.
Danny Fenton/Phantom (Danny Phantom) firing a ghost ray from his rear.
Meelo (Avatar: The Legend of Korra) demonstrates his Fartbending.
Luigi (Super Mario series)
Both Hibari and Haruka (Senran Kagura) primarily use their butts in tandem with hand to hand combat prowess and Ninjutsu.
The Biotroids (Teenage Mutant Ninja Turtles 2012) have fully functional laser guns in their rears.
Rin Rokudo and Sayaka Miyata (Keijo!!!) battling it out with their butts at speeds faster than the human eye can see.
Kotone's butt (Keijo!!!), Cerby, is able to automatically attack, chase, counter and dodge attacks from Kotone's opponent all by itself without her having to do anything. This allows her to conserve her energy for special moves like the "Rising Dragon Breast".
Non Toyoguchi (Keijo!!!) is a counter fighter, the relies on her dumb luck and huge butt to win her races. Her huge butt is incredibly soft, capable of bouncing her opponent away and deflecting her opponent's attacks against them.
Kobayakawa (Keijo!!!) is a Keijo instructor with uncanny accuracy with her butt, using it to shoot her chalk holder to hit Nozomi square in the forehead.