Graven Deep
Island beach, then an undersea Dwemer observatory. Three main bosses and three optional secret bosses. Each secret boss gives the group a buff for the rest of the run.
- Hard mode banners unlock in order. Varzunon HM requires an HM Gatekeeper kill first, and Zelvraak HM requires HM kills on both earlier bosses.
- Poison synergy (trash too): Pangrits (guar-like adds) can poison you. Use the synergy on a glowing pangrit mound, or away from the group.
- Wraiths after Varzunon: their heavy attack can one-shot a tank who isn't blocking. Block, and break free from their fear fast.
Mzugru, Security Drone
Secret bossHow to spawn: After the first island packs, take the side trail right to a trapdoor (the Security Depot). Turn the Control Knobs in this order: Delta, Beta, Alpha, Gamma.
Easy fight.
- Block the heavy and spin attacks. Everyone else steps back from the spin, which knocks you down.
- When the boss is shielded, break the Power Transmitter pylon at the side of the room. The boss is immune until the pylon is down.
- A Dwarven Centurion inside a barrier, surrounded by four puzzle cubes. Lightning bolts arc up, then land as lightning AoEs.
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Buff Shield Generator: +10% Max Health. When you're hit, a Centurion Shield halves the damage you take for 3s (40s cooldown).
- The knob order comes from only one guide (ArzyeL/Fextralife). Alcast just says 'correct order'.
The Euphotic Gatekeeper
Boss- Poison synergy: when you get it, run to a glowing Pangrit burrow and use it there to close the burrow. If you can't reach one, use it away from the group. If you never use it, it explodes on you.
- Stay out of the poison pools left behind. They do heavy damage over time.
- The boss runs around the room but comes back. Don't chase him, just keep taunt. Pick a wall spot and hold it.
- Pick up any Pangrits from open burrows and face them away from the group (they cleave).
- Get out of his path when he charges or rolls. He knocks people back.
- Keep the tank topped. Light attacks stack bleeds and armor debuffs on the tank.
- The boss is a big red crab-folk (Hadolid) with a sword.
- Burrows are dirt mounds that glow while they're active.
- When he teleports he leaves a decoy husk with a growing AoE. Back away before it explodes.
Activate: Banner before the boss (veteran).
- More HP and damage. No new mechanics.
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Pre-fight: he's invulnerable until all three starting burrows are closed with poison. Pangrits keep spawning until then.
During the fight new burrows open and someone gets poisoned again. Closing a burrow also kills the Pangrits next to it.
- The exact on-screen color of the poison debuff (probably green).
Xzyviian, Defense Crawler
Secret bossHow to spawn: In the Dwarven Station, turn right at the three-way fork into the laser corridor. Crouch, jump and time your moves to get through. Pressure plates act as checkpoints. Only one player needs to finish it, and Streak or another gap-closer helps.
Easy fight. Stay out of the fire cone and the fire pools.
- Block its heavy attack. One guide says it can one-shot.
- A large Dwarven spider. It breathes a frontal fire cone, and its fire projectiles leave burning pools.
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Buff Defense Systems: +10% Max Magicka, plus you can fire the base's laser defense stations at enemies (60s cooldown each).
Varzunon
Boss- Kill the glowing blue Skeletal Sacrifices before they reach the boss. Each one he absorbs makes him bigger and hit harder, and a fully grown Varzunon can one-shot.
- Necrotic Cage: when a groupmate is held up in a giant skeletal hand, burst the hand to free them before they die.
- Hold the boss in the center. Keep the small skeletons on the group so DPS can AoE them.
- Block or move out of Stomp (rows of ground AoEs).
- Priority: Sacrifices, then the cage hand, then skeleton mages, then the boss. AoE the small skeletons.
- Necrotic Rain (blue-fire meteors) hits everyone at once. Keep the group stacked and pre-heal.
- Sacrifices: big skeletons glowing bright cyan, walking slowly toward the boss.
- Stomp: a predictable line of ground AoEs.
- Cage: a giant bone hand lifting a player into the air.
- High DPS: keep him center and burn. He dies before growth matters.
- Slower groups: Sacrifices come from 3 of the 4 walls. Take the boss to the empty wall, behind a pillar, to buy time for killing them.
- Frost Blockade (ice staff wall) blocks the Necrotic Rain projectiles.
Activate: Banner before the boss (veteran). You must have killed the Gatekeeper on HM first.
- More HP.
- Likely twice as many Sacrifices and more adds (per UESP). Have a DPS ready on them.
- Likely Stomp fires three rows in a T shape, with the middle row aimed at the tank.
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He works like the Gravelord in Skyreach Catacombs: he starts weak and scales with every Sacrifice he absorbs. If he gets huge, melee players have to look up to target him. The achievement 'A Bone to Pick' requires letting him reach max size.
- HM changes: UESP lists the extra Sacrifices and the T-shaped Stomp, but Alcast, ESO-Hub and a 2025 forum guide all say 'same as veteran'.
Chralzak, Sphere 9402-A
Secret bossHow to spawn: In the Tempest Observatory, take the slightly hidden left turn to the far south. It's a shock-tile puzzle: six levers each toggle a set of tiles (look at a lever to see which). One player crosses the tiles while another works the levers. Pull the far lever at the end and the sphere rises from the floor.
Easy fight. Step back from the spin and out of the lightning zaps.
- A Dwarven sphere that pops up out of the electrified floor.
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Buff Remote Battery: +10% Max Stamina. At 30% Stamina or lower, Stamina Recovery is supercharged for 4s (60s cooldown).
Zelvraak the Unbreathing
Final boss- Sea Orbs: never let one touch the floor. That wipes the group. Hit a falling orb with any attack and it bounces back up. Orbs can't be killed. Vet has 2 orbs, HM has 4.
- Sundered Soul: a gold line shoots out from you. Run along it right away and touch your golden ghost at a corner pad. You can't be healed until you do.
- Fear (skull over your head): turn your character to face away from the boss until the skull disappears.
- Heavy cone: never stand near the tank's facing direction.
- At 50% (Afterlife): stay out of the center. Standing there kills you.
- Hold him near the middle and aim his heavy cone in a cardinal direction, never at a corner (the soul pads are in the corners).
- Each cone leaves a shade that repeats it later, so stack every cone along the same line.
- Right after the Afterlife he casts a cone immediately. Re-taunt him and the Flesh Abomination and line them up again.
- Slot a ranged skill so you can hit the orb behind you while blocking.
- At 75% and 25% he splits into 4 copies on the 4 corner pads. One player per pad: bash-interrupt your copy and kill it, then help the others.
- In the Afterlife, AoE the Fractured Souls swimming toward the center. When it ends, kill the Flesh Abomination first.
- You own the orbs. Sweep a heavy attack (resto or lightning) across them. On HM: healer covers 3 orbs, tank covers 1.
- If he steals a Nightblade's class, purge the DoT he puts on the group.
- Orbs: whirlpools appear on the ceiling, then a teal water sphere with spray slowly sinks. You can hear it as it nears the floor.
- Class steal: he waves his wand at a player and the two braziers over his shoulders change color: red = NB, blue = Sorc, orange = DK, yellow = Templar, green = Warden, purple = Necro, none = Arcanist.
- Afterlife: the screen goes dark and everyone looks ghostly. Yellow ghosts wander the room; touch them for healing and speed.
- Don't let a 75% split land on top of a Sundered Soul. That's 'almost always a wipe.' If he's at 76–77% when the soul mechanic is due, either push to 75% fast or hold damage.
- Your soul always flies to the farthest corner pad. Stand near the center facing away from the farthest corner so you're already pointed the right way.
- Frost Blockade absorbs his fireball projectiles.
Activate: Banner before the boss (veteran). You must have killed the Gatekeeper and Varzunon on HM first.
- 4 Sea Orbs, spawning in pairs.
- Sundered Soul hits 2 players. Souls can't share a pad, so yours may go to the second-farthest corner.
- Class steal also gives him a defensive ability: heal circles on the ground (yellow telegraphs; pull him out of them), damage shields (burn through), or for Necro/Arcanist two Spirit Mender adds (kill them).
- The split copies also steal the class of whoever is standing closest.
- Dead players leave a grave that keeps raising skeletons until someone kills it. Avoid deaths.
- With stacked cones, the tank should dodge-roll backwards rather than block.
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Class steal (Soul Siphon): he takes one attack from the class of the player he hits. NB = purgeable DoT. Sorc = lightning AoEs under everyone. DK = fireball barrage. Templar = novas. Warden = slippery ice patches that can ruin a dodge-roll. Necro/Arcanist = Blastbones.
Afterlife (50%): he goes invulnerable in the center. Every Fractured Soul that reaches him makes the Flesh Abomination that spawns afterward stronger.
Orb count resets after the 50% phase, and orbs start again around 40%. Kill the Flesh Abomination before you push him to 40%, so it doesn't overlap with orbs.
- The split thresholds (75% / 25%) come from Alcast and ArzyeL. Other guides only say 'twice'.