Gameplay spoilers are different than plot spoilers, and people might not expect the first despite the spoiler tag. Oh well, I'll leave it off.
Anyhow you're making me doubt myself so I'm going to have to go and check sometime soon. :) I'm pretty sure it's survivable though. Also that's not the monster I had in mind, but I can't find any notes about whether I tried a Rakshasa or not. I feel like I must have... I was thinking of a Naga. Your AGL is low enough that you almost always go second, which is generally more reliable than going first with high AGL against Apollo. At very high AGL (> 99) the turn order can get quirky.
Not sure why you didn't just say that in the first post, lol.
At very high AGL (> 99) the turn order can get quirky.
When I did a 4 Monster party, I ended up giving Speedups to Dad in order to massively buff his Agi in the pre-taunting Apollo phase. He ended up quite reliably going first with the Heal Staff repeatedly, although I must've used enough to put him well over 100 Agi during the fight (assuming the game lets you boost it in battle past the 99 mark).
Actually, it seems it is possible to survive the explosion even if Dad's dead. Found a video where a Human + Mutant were only hit for 250 ish:
Guess I've never had a win where Dad got killed in the fight.