Very interesting roster i see you've taken inspirations from Injustice: Gods Among Us concept wise with the touch of DC Universe and Marvel Universe which it's pretty cool.
Yet i wouldn't mind to see the crossover happen if they would cooperate each other and and have other developers who are well balanced in other fighting games that knows strength and weaknesses if that's the case.
DC: Superman, Cyborg, Raven, Lex Luthor, Deathstroke Batman, Nightwing, Catwoman, Joker, Harley Quinn Wonder Woman, Shazaam, Aquaman, Ares, Black Adam Hal Jordan Green Lantern, Hawkgirl, Lobo, Sinestro, Poison Ivy Flash, Martian Manhunter, Green Arrow, Captain Cold, Doomsday Hidden - Rorschach, Doctor Manhatten Boss - Darkseid
Marvel: Captain America, Spider-Man, Starlord, Venom, Doctor Octopus Ironman, Wolverine, Storm, Magneto, Mystique Thor, Ghost Rider, Doctor Strange, Winter Soldier, Loki Hulk, Mr. Fantastic, Silver Surfer, Dr. Doom, Dark Phoenix Scarlet Witch, Iron Fist, Punisher, Deadpool, Ultron Hidden - Daredevil, Ant Man Boss - Thanos