Arcturin, the Lich King
From Nevergrind Wiki
Arcturin, the Lich King is the Final Boss of Act 2. He appears in the Arcturin's Crypt 3 zone after completing the prerequisite portion of the quest, Laid to Rest. As with most other bosses he has innate Crowd Control Reduction through the Dauntless Affix and is immune to Charm spells. He is level 32 on Normal Difficulty, 66 on Nightmare and 85 on Hell.
Abilities and Affixes
Normal
On Normal Difficulty Arcturin is Magic Resistant and casts Rune, Blizzard and Ice Shard.
Nightmare
On Nightmare Difficulty Arcturin gains the Cold Enchanted Affix and the spell Sanctuary.
Hell
On Hell Difficulty Arcturin gains the Lamprey Affix.