Originally Posted by
NvrMore
Memory's a little rusty..
Mach speed is the key. basically mach one of the boulders until joe starts glowing, that'll allow you to get in next to leo without his fireballs toasting you. Mach the rock next to him to replenish your burn, hit him and jump away.
Rinse and repeat
When he gets into spinning, dodge the blows according to where the sculls appear (e.g. duck when skull high). After five sequential dodges he will stop and look dizzy. slow/zoom-punch him 3-4 times and then retreat.
Rinse and repeat.
I think there's a little more filler to it, but they're the essentials.