I just finished playing impossible Paladin with just thorn hunters and thorn warriors. Got the Crown (+100% damage), Hagrid, botany diploma and thats all what i needed. The battle is over about 4-5 turns, ressurection just takes time.

First boss is easy as it gets, spider boss was very time consuming :) used the "magic axe" tactic and from there on, it got a somewhat boring, because thorns are REALLY overpowered with Hagrid and his ress ability - 72-111 thorns in every turn :-P

Finished in day 1, score was 1110 something.

Now, if Hagrid was just on OotM, it would be so easy now (seriously overpowered). Just put some fire resist items and they are God-Like

Hagid also ress Ents and Ancient Ents.
Ancient Ents have the most HP from all creatures, at lower lvls they make the battles a bit easier.