good guys: the MUGEN Realm guardians (Dee Bee Kaw, Pepito, Juan, Daniel9999, Adam Admundson, Madoldcrow1105, Toonalexsora007, Big Eli King, Franko Pedalovsky, Dragon Claw, Shun Kurasawa (also known as "Kung Fu Man") and his daughter Rena Kurasawa (also known as "Kung Fu Girl")
bad guys: Elque (main), Abyss, OMEGA Tiger Woods, Zun Kurasawa (Shun's dead brother, revived as "Evil Kung Fu Man"), Dooby Dummy, Rario, ADOM the ADOM, Weegee, Barney, Hazama, Dio Brando, Bishamon, Demitri Maximoff, Kang, the Giant Chicken, Frieza, Babidi, Ace Killer, Yukari Yakumo, Flandre Scarlet, Mima, Oroku "The Shredder" Saki, Krang, Keldor "Skeletor" of the house of Grayskull, Megatron, Red Skull, Carnage, Venom, Shuma-Gorath, Spawn, Akuma, Balrog, Sagat, Seth, Vega, Master Bison, Shao Khan, King Bowser, Kamek, Dr. Ivo "Eggman" Robotnik, Bass, Mewtwo, Gengar, Rampardos and Onix
minor characters (neutral): Jin Kisaragi, Hakumen, Noel Vermillion, Ragna the Bloodedge, Jotaro Kujo, Anakaris, Felicia, Hsien-Ko, Jon Talbain, Rikuo, Lord Raptor, Morrigan Aensland, Sasquatch, Victor von Genderheim, Homer Simpson, Bart Simpson, Bender Bending Rodriguez, Turanga Leela, Peter Griffin, Ren Hoek, Captain Caveman, Fat Albert, Underdog, Duck Dodgers, Mordecai, Rigby, Finn the Human & Jake the Dog, Spongebob, Zack "Gumball" Watterson, Beavis, Butt-head, Lion-O, Son Goku, Vegeta, Son Gohan, Hercule Satan, Naruto Uzumaki, Ichigo Kurosaki, Monkey D. Luffy, Inuyasha, Kenshiro, Seiya de Pegasus, Kirito, Asuna, Haruhi Suzumiya, Gilgamesh, Yoko Littner, Natsu Dragneel, Erza Scarlet, Gray Fullbuster, Tifa Lockhart, Edward Elric, Shin Hayata (Ultraman), Dan Moroboshi (Ultraseven), Reimu Hakurei, Marisa Kirisame, Alice Margatroid, Yuyuko Saigyouhi, Byakuren Hijiri, Sakuya Izayoi, Hong Meiling, Patchouli Knowledge, Eirin Yagokoro, Komachi Onozuka, Yuugi Hoshiguma, Leonardo, Donatello, Raphael, Michaelangelo, Prince Adam "He-Man" of the house of Randor, Optimus Prime, Rainbow Dash, Popeye, Fred Flintstone, Captain America, Cyclops, Deadpool, Iron Man, Black Widow, Hulk, Spiderman, Thor, Wolverine, Hawkeye, Ironfist, Moon Knight, Batman, Superman, Cyber-Woo, Rorscharch, Blanka, Cammy, Chun-Li, Dhalsim, Edmon Honda, William H. Guile, Ken Masters, Ryu, Zangief, Guy, Cody Travers, Juri Han, Crimson Viper, Thunder Hawk, Sakura Kasugano, Dan Hibiki, Reptile, Scorpion, Sub-Zero, Eric Theodore Cartman, Kenny McCornick, Master Shake, James "The Angry Videogame Nerd" Rolfe, Doug "Nostalgia Critic" Walker, Annoying Orange, ALF, Derp Herpington, Mario Mario, Luigi Mario, Peach Toadstool, Yoshi, Wario Wario, Waluigi Wario, Donkey Kong, Kirby, Meta Knight, Link, Fox McCloud, Samus Aran, Little Mac, Capt. Douglas Jay Falcon, Hunt "the Dog" & a duck, Sonic the Hedgehog, Megaman, Roll, Protoman, Tron Bonne, Megaman X, Zero, Maguhmeen (AKA: Bad Boxart Man), Pac-Man, Banjo & Kazooie, Crash Bandicoot, Solid Snake, Snorlax, Blaziken, Gardevoir, Lucario, Ivan "The Heavy" Von Cherinkov, Madotsuki, Ristar, Dynamite Headdy, Ronald McDonald, Colonel Harlan David Sanders, Dancing Banana, Pepsi Man, Sacola Man, SPY-DAMA, Shaquille O' Neal, Pingu, Don Ramón Valdés, John Rambo, the Cursor, King Harkinian of Hyrule, Hotel Mario Mario, Oro "Yee" & Peek "Paa", Doge and Zeeky H. Bomb