Glacius, the Frozen Wyrm
BossFought on floors 60 and 70, in Act 4: The Frozen Reaches. Floor 70 is this act's climax fight.
Mythic, cursed, and divine relics sit above legendary, the fusion ceiling, and drop only from boss and guardian kills: mythic from floor 50, cursed from floor 80, and divine from floor 90. Here, a mythic relic can drop from its floor 60 and 70 kills.
Abilities

Frostball
Blasts all enemies for magic damage and may stun them.
- damage, power 10 + 0.9×magic
- status, applies Stunned (stun, 1t)


Rejuvenation
Heals the whole party a little now and grants regen.
- heal, power 8 + 0.4×magic
- buff, applies Regeneration (hot, 3t)
Statuses It Inflicts
Inflicts:
Stunned
Regeneration
How to Prepare
- You fight Glacius, the Frozen Wyrm solo, and there is no rest heal before the encounter, so arrive with real HP in the bank and sustain already flowing: lifesteal earned in the fight itself, plus potions bought with gold beforehand.
- An escort wave of the biome's regular enemies fights first. Only after they fall does Glacius, the Frozen Wyrm step out alone for the closing wave, so keep enough HP and cooldowns in reserve for the real fight.
- Its kit includes a heal. It fights its own wave alone, so that heal restores its own HP: bring enough sustained damage to outpace it, not just one big burst.
- It can buff its own stats mid-fight, so the fight gets tougher the longer it drags on, not easier.
- It can stun you, skipping one of your turns outright, so don't fight this one on a razor-thin HP margin.
- If you wipe, you restart at floor 1, but your permanent upgrades and talents carry over, so a loss here is a setback, not a full reset. Optional Hardcore mode also destroys your equipped gear on a wipe.