Sulfen, the Brimstone Matriarch

Boss

Fought on floors 20 and 30, in Act 2: The Brimstone Reach. Floor 30 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, but only on Infernal. This fight sits below all three gates, so no apex relic drops here.

Abilities

Arcane Bolt

Targets enemy · Every turn

A reliable single-target magic missile.

• damage, power 6 + 1.1×magic

Triple Shot

Targets enemy · 2000-turn cooldown

Three swift arrows at one enemy.

• damage, power 8 + 0.8×attack
• damage, power 8 + 0.8×attack
• damage, power 8 + 0.8×attack

How to Prepare

• You fight Sulfen, the Brimstone Matriarch 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 Sulfen, the Brimstone Matriarch step out alone for the closing wave, so keep enough HP and cooldowns in reserve for the real fight.
• It carries a ramping enrage from its very first turn: the longer the fight runs, the more true damage it drains from you every turn, so do not stall.
• Its Void Aegis caps every single hit you land to 12% of its own max HP, so no single burst can delete it early. Expect a longer fight than your raw damage numbers suggest.
• 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.