Anything goes, make up your own rules if you got any ideas.
Anyhow:
1) Agni and Rudra the Firestorm vs Plusle and Minun
2) Mundus (DMC) vs Shao Kahn
3) Griffon vs Avion (Shadow of the Colossus)
4) Nevan the Lightning Witch vs Phosphora (Kid Icarus Uprising)
5) Vergil (DMC) vs Auron (Final Fantasy X)
6) Mundus (DmC) vs Lex Luthor
7) Echidna the She-Viper vs Medusa (Kid Icarus Uprising)
8) Dante (DMC) vs Laharl
9) Dante (DmC) vs The Avatar (The **** for brains from Ultima IX)
Anyhow:
1) Agni and Rudra the Firestorm vs Plusle and Minun
2) Mundus (DMC) vs Shao Kahn
3) Griffon vs Avion (Shadow of the Colossus)
4) Nevan the Lightning Witch vs Phosphora (Kid Icarus Uprising)
5) Vergil (DMC) vs Auron (Final Fantasy X)
6) Mundus (DmC) vs Lex Luthor
7) Echidna the She-Viper vs Medusa (Kid Icarus Uprising)
8) Dante (DMC) vs Laharl
9) Dante (DmC) vs The Avatar (The **** for brains from Ultima IX)