Not normally at level 8 when the spell becomes available. I think too many of you are thinking "When I'm high level and have 100% resist and this spell heals me instead of damages.. I don't see the problem..".
I got the spell around level 10. My warrior still takes damage from using it, but they are also a tanky warrior. This playthrough wound up being easier than I would have liked (I got Leech and Glass Cannon on my people before realizing how OP they are, and don't fancy respecing). So either with that in mind, or regardless, I don't consider the minor damage from burning to be that big of a deal.
See, I have a tanky warrior and another warrior (Madora) who focuses on damage. She is not built to tank, and is the one I give Phoenix Dive to. My "tank" generally doesn't want to evac out of danger (I spend a great deal of effort getting him into danger on purpose), nor does he need to be abandoning his defensive position while surrounded by melee opponents to strike down a caster deep behind enemy lines and leave the rest of the party behind him exposed and vulnerable.
So, to me Phoenix Dive is more of an offensive ability rather than a defensive ability. And it used to be really great for offensive builds.. right up until they decided to light the caster on fire.
I avoided Leech because I knew from testing that it was pretty overpowered.
