3500HP ---> 22lvl At 12-13levels ---> about 1800HP His resistances for fire about 70% poison about 15%. 1 skill point to geomancy allows self cast of Earth shield for another 1500HP and poison resistance as bonus.
Your super-killing daemon is actually week, anyway. My party was wiped out on 3-7 lvl, when its easy to find over-level opponent. And player usualy sufer by missing skill books in shops. Later 10-14lvl no party wipe at all. Later 16+ I dont remember a dead member in a battle. Final battle - pure joke. Most epic battle I have had is the clean out Hunter Vilage. Weak oponents but epic scale, I would recommend to spawn(call reserves) about more 12 staple orcs to make it challenging. Also remove 2-3 common highlanders would help.
I hope that Larians make an veteran beta. For gathering feedback on skills and difficulty tuning.