Chaos vs Emperor

I would say Chaos. Well, it's a close match, so, this is only a probably.

Chaos vs Zeromus

Definitely Zeromus.

Chaos vs ExDeath

ExDeath would probably win here.

Chaos vs Kefka

Hm, Kefka.

Chaos vs Sephiroth

Definitely Sephiroth. Heartless Angel Pale Horse kthxbai.

Chaos vs Ultimecia

Ultimecia deserves some love. And she has five freaking forms!

Chaos vs Kuja

Kuja.

Chaos vs Seymour

As Huxley would say, "None are a match for Seymour Guado".

Chaos vs Shuyin

I'm not sure about this one, because I've never finished X-2. But as long as Shuyin can deal 2,000 points of damage, I'm sure he'll be okay.

As neat as Chaos is, he isn't one of the more powerful villains, if only in comparison.