Boss Codex

In the labyrinth a boss bars the way every 10 floors, and on a few special floors. All bosses are one of four wardens. You first meet them one by one on floors 10, 20, 30 and 40; after that, the four take turns returning in stronger forms. This page lists each warden’s stages and how to beat them.

What every boss has in common

Red circles: the Bone Marshal, the Grave Ritualist and the Grave Tax Collector paint a red circle on the ground, then detonate an area attack there. The circle is exactly the hit area, and its position locks the moment it appears. When you see one, step out right away.
Brands and harvests: some bosses brand corpses. If you use a branded corpse first — for a summon, a Corpse Explosion or Absorb — before the boss harvests it, the harvest fails and the boss staggers.
Minion hunting: some bosses mark one of your minions and focus it down. When a marked minion falls, its Command comes back, so summon again to refill the front line.
Rewards: every boss kill drops guaranteed gear carrying one of that boss’s own Exotic options. Kill the same boss enough times to reach its ceiling and a special drop is guaranteed.

More dodging tips are in Floors, Combo & Grades, and where each boss appears by zone is in Zones & Affixes.

Bone Marshal

The first warden you meet, and the one that breaks your line by force.

How it fights: charges through your front line, then detonates a wide red circle. Anyone left inside takes heavy damage and is briefly stunned. It also calls adds and marks one of your minions to hunt.
How to beat it: its circle is wide with a slightly longer warning, so move well away as soon as it appears. Put a Tanker in front to absorb the charge and your ranged minions behind stay safe.
Gear it tends to drop: Corpse Explosion gear

Grave Ritualist

A boss that feeds on corpses and grows stronger the longer the fight drags on.

How it fights: brands corpses and harvests them to heal and raise more adds. It uses a small, fast red circle.
How to beat it: use branded corpses the moment you see them — summon, Corpse Explosion or Absorb. A failed harvest staggers the boss and cuts off its healing and reinforcements. The circle is small but quick, so a short sidestep is enough.
Gear it tends to drop: minion and Bleed gear

Grave Tax Collector

A boss that fights from behind a crowd of adds.

How it fights: fights with a retinue of adds, brands corpses and charges. It uses a small, fast red circle and marks one of your minions to hunt. It brands corpses but never harvests them.
How to beat it: clear the crowd with Corpse Explosion to open a path to the boss. The corpses its adds leave behind become fresh summoning material.
Gear it tends to drop: Command gear

Soul Legate

The commander of the four wardens, mixing every trick they have.

How it fights: charges, summons adds, brands and harvests corpses to heal, and hunts your minions. It is the only one of the four that never uses a red circle.
How to beat it: there’s no ground warning, but the pressure never lets up. Use branded corpses first to cut off its healing, and resummon marked minions as soon as they fall to keep your line intact.
Gear it tends to drop: Teleport gear