I'm not sure if green flame would affect him like regular fire would.
If you don't bring fire, Martian Manhunter probably kicks more ass than just about anyone. He's of the universes most powerful telepaths, can transmute himself, Strength speed and durability on par with supes. Super healing. Invisibility, intangibility, all the sight and sound powers of supes, plus he has eleven senses rather than 5.