i agree with diego. It is easier to get ur health down fighting the robot on 24b. Fighting the 3 black kelolans is a bit risky.
As a side note, i found he always used reflect against me in the second round. So for this one, i used status ailments spells (poison etc.) as they had no effect when he reflected them back.
When i finally beat him, i got him in round 3, the last reversa before annihalation was coming. I think it was my 4th time against him, i was so relieved