I'd love to see the roster get set up as counterparts with a 40 fighter roster + DLC

My picks would be

1. Superman vs Wolverine (Both are the name most Synonymous with their company. Both are nearly invincible. Both deal with being unable to lose in a straight-up fight by having storylines revolve around personal drama.)

2. Batman vs. Iron Man (Both are rich. Both rely on gadgets. Both are among both companies most popular heroes.)

3. Wonder Woman vs. Thor (One is the Norse god of thunder, the other is the chosen champion of Athena, the Greek goddess of War. Both are nearly invincible. Both have storylines that revolve around mythology.)

4. Green Lantern vs. Spider-Man (Both can create any object they desire through either a power ring or web shooters. Both are driven by a sense of duty.)

5. Green Arrow vs. Captain America (Both are idealists who aren't as flashy as the other heroes but manage to get the job done anyway. You also can't have Justice League without Green Arrow nor can you have the Avengers without Cap.)

6. Black Canary vs. Storm (Both are female. Both are known for leadership abilities. Both have projectile powers. It was tough deciding on Cyclops or Storm to fight Black Canary, but Storm won out in the end.)

7. Cyborg vs. Cable (Both are half mechanical. Both rely on projectile attacks. Cyborg is able to create any piece of machinery from his mind. Cable is a powerful telekinetic.)

8. Swamp Thing vs. Hulk (They're two big green things who want to be left alone and neither can be truly defeated.)

9. Catwoman vs. Black Widow (Both are anti-heroes. Both rely on gadgets. Both prefer hiding in the shadows to fighting one on one.)

10. Grifter vs. Psylocke (Two telekinetics who are also weapon experts. Psylocke prefers swords and knives, Grifter prefers guns.)

11. Darkseid vs. Apocalypse (Even though this could be broken down into Darkseid vs. Thanos or Apocalypse vs. Black Adam but two big blue guys who want to take over the world slugging it out is too cool to pass up.)

12. Lex Luthor vs. Doctor Doom (Lex's closest counterpart is Sebastian Shaw, with other options being Kingpin, Green Goblin and Red Skull but Doctor Doom won out in the end simply through sheer awesomeness.)

13. Doomsday vs. Juggernaut (The villain version of Swamp Thing vs Hulk)

14. Joker vs. Carnage (Both are sociopaths who laugh in the face of their victims and treat it as one big joke)

15. Ares vs. Dormammu (One is the god of slaughter and bloodshed, the other was Satan when the Comics Code prevented him from actually showing up. It was a tough choice to choose between Dormammu and Loki but Dormammu wins because of how awesome he is.)

16. Bane vs. Nuke (Roided up supervillains who no real superpowers who are still a threat to both Batman and Daredevil.)

17. Genocide vs. Stryfe (One is an evil future version of Wonder Woman the other is an evil clone of Cable from the future.)

18. Brainiac vs. Ultron (Evil robots FTW)

19. Firefly vs. Zeke Stane (Both wear high tech suits of armor to conceal not actually having superpowers. Both are villains.)

20. Magog vs. Venom (This is what happens when ant-heroes grow too dark to the point where they become villains)

Season Pass 1

Pack 1
Shazam vs. Ms. Marvel (Who doesn't want a fight over who's the REAL Captain Marvel?)

Pack 2
Nightwing vs. Daredevil (Neither have superpowers and rely on martial arts to deal with evil. Both lost their fathers in tragic circumstances.)

Pack 3
Flash vs. Northstar (This should end up being DLC since neither Quicksilver nor Northstar are cool enough to make the cut for the main roster and they're the only to options that come to mind)

Season Pass 2

Pack 1
Scarecrow vs. Mr. Fear (Both use fear gas as their main weapon)

Pack 2
Baron Zemo vs. Ras Al Ghul (One is a Cold War era face of Communist terror, the other is a modern take on radical Islam. Both have private armies carrying out bombing and assassinations across the globe.)

Pack 3
Lobo vs. Deadpool (It'll be a laugh riot)