Not sure how many hp he has, but it is a heap. I don't remember what level I was but I think 92 sounded about right for me. I found the boss to be pretty easy personally. I mean I didn't grind at all to beat him, and got him on my first attempt. Milkey way had a helluva time killing him though. Just be aware there are 3 phases pretty much, the first is how he starts, this in my opinion is the rough part. If you have someone important die on the first phase just restart and try again, you know you hit phase 2 when it starts changing colors. Each color represents an element and weakness. use wind spells to kill green, fire to kill blue, nature to kill yellow, cold to kill red, mystic to kill light blue, and spirit to kill purple. The last phase is when he goes back to his first appearance again (kinda like purple, only less streaks and purple colors around the boss). At this point he's almost dead, and doesn't really seem to do anything extra badass other than a cease of weaker element spells. Use his elemental weaknesses and the fight goes much quicker. I reccomend making sure your nature guys are immune to paralize, and your fire dudes are immune to silence since those of opposite elements tend to do those status ailments.
ANYWAY. I just pawnt final boss mk 2, I guess I was way too high level at this point (never bothered to attempt her, was too scared, thought she'd be way harder). I rather like some of the spells the new characters get, their stats are god-awful though.
But I was curious, way early int he game I benched cirno because she was too squishy, and I figured I'd get another slower in the game. Then later on when it became apparent that there wouldn't really be many, I continued to leave her benched because every boss I fought seemed to be immune to status debuffs (I know this because Alice's spells never ever debuffed bosses). So I figure wtf is the point of having a sub-par character around just for a debuff that every boss would be immune to anyway.
But then I read somewhere that icicle fall slows no matter what, no immunities. Is Cirno the only character in the game with such a slow?