Ok so my main problem is the right hand side. Im seeing some great depth effects on the left but the right is just space with random distracting effects.
Also loose the border. Neither work, this would look better "raw" imo
To me, this definitely feels like he's fighting his way through a cavern full of lava which is SO AWESOME. But I agree with x that the right side is a little weird.
I'd try darking and reddening it to make it fall back to the same depth as the background on the left side.
Dunno if this will mess with the feel of lava-battle, though.