User blog comment:Omnicube1/ROUND 4: Big Boss (Metal Gear Solid series) vs. Alex Mercer (PROTOTYPE)/@comment-2016768-20100923143604

Villains fight list:

Swiper (Dora) vs. Dr. Doofenshmritz (Phienas and Ferb)

The Hacker (Cyberchase) vs. Dr. Drakken (Kim Possible)

Brain Freeze (Johnny Test) vs. Count Spankula (Codename: Kids Next Door)

Yzma (The Emperor's New Groove, etc.) vs. The Dark Lord Chuckles the Silly Piggy (Dave the Barbarian)

Plankton (Spongebob) vs. Man-Dark (Dexter's Lab)

I dunno maybe I'll have more ideas but not sure. If you haven't heard of any of these characters, just Google search them and I'll bet you find something.