The immortal was PISSING ME OFF with divide!
so I straight killed him. Never used reversa. What i found useful was:
The critical boost skills
3 combo
all immortals (duh) mortals seemed useless for more than one cheap move in the beginning, and reviving them is a waste of a turn
All-powerus
Faster (on the combat immortals mortals using 3 combo)
and gamble, when it got down to the wire and i didn't know how much health i would have left by the time i got reversa off.
My immortals were all around 80 and i finshed him with Kaim and Sarah left standing, both critical. one more shodowus and i was toast, unless i was lucky enough to absorb it.