User blog comment:Deadpool fan11/I demand a marvel vs dc videogame/@comment-4907202-20120609185313

Bizarro vs. Red Hulk Azazel vs. Azazel Captain Marvel (Genis-Vell) vs. Captain Marvel/Shazam Venom vs. Parasite Deadpool vs. Deathstroke Lady Deathstrike vs. Deathstroke (see what I did there?)

Also costumes: Spider-Man: Classic, Symbiote, Future Foundation, Ben Reily, Scarlet Spider, Ultimate, Noir, 2099, Spider-Armor, Iron-Spider Captain America: Modern, Classic, U.S Agent Dr. Strange: Modern, Classic, Original Deadpool: Classic, Ultimate, X-Force, X-Men, Dea- Iron Man: New Avengers, Original, Gold, Classic, Hulkbuster Thor: Modern, Classic, Ultimate Superman: Classic, Black

Still editing, but some characters just can't have alternate costumes.