Diablo 4 Duriel boss: How to get Shards of Agony and Mucus-Slick Eggs

The Duriel boss is Diablo 4's most significant endgame challenge—besides pushing into high-tier Nightmare Dungeons, that is. The King of Maggots is the toughest of the new bosses that Blizzard added to the game as part of the Season of Blood, and that's not just in terms of fighting him. 

While his summoning material farm isn't quite as annoying as The Beast in the Ice, it's still a lot of work to get what you need considering he's the only boss that requires two materials instead of one. Duriel does have a chance to drop Uber Unique items, though, which is reason enough to fight him. If you're curious about what he drops, check out our Diablo 4 boss loot tables. Otherwise, here's how to summon the Duriel boss.

Where to find the Mucus-Slick Egg and Shard of Agony

There are two separate materials you need if you wish to summon the biggest of bads, Duriel, on Torment world tier. You can get these by beating some of the other endgame bosses:

• Shard of Agony: These drop from defeating Grigoire in the Hall of the Penitent on Torment world tier. You'll need five Living Steel to summon this boss, which means you'll have to open two Tortured Gift of Living Steel chests in Helltides, costing you 600 Aberrant Cinders overall. This is definitely do-able in a single Helltide and since each chest gives you three Living Steel, you'll have one leftover for your next summon.
• Mucus-Slick Egg: These drop from defeating Varshan beneath the Tree of Whispers on Torment world tier. To fight the corrupted priest you'll first need to gather a Gurgling Head, Blackened Femur, Trembling Hand, and a Malignant Heart. All of these come from Tree of Whisper caches or from the Grotesque Debtor enemies who have a chance to appear after world bosses or in other activities—keep an eye out for the notifications that one is about to spawn nearby.

Always remember, these materials are only available from either boss on Torment world tier, so refrain from fighting Grigoire too much until then so you don't miss out on rewards. Varshan, on the other hand, is very easy to get summoning materials for since you complete Whispers all the time, so there's no real harm in fighting him on Nightmare if you're looking to try one of the new bosses out.

How to summon the Duriel boss

To call up Duriel, King of Maggots, you're going to need:

• Two Mucus-Slick Eggs
• Two Shards of Agony

This means defeating Varshan and Grigoire twice a piece. Duriel is also a level 100 boss, so make sure you're high enough to actually defeat him and deal adequate damage. Stacking some Emeralds on your jewellery for the extra Poison Resist will also help.

Once you've got what you need, travel to the Gaping Crevasse dungeon in Kehjistan, just to the south of Gea Kul at the very bottom of the map. There are a few waves of level 100 enemies you have to fight through before you get to the boss room, but once there, whack your materials into the Pestilent Altar to call Duriel. 

Remember, if you don't feel the most confident, you can always party up—there are usually a fair few people hanging out at the dungeon entrance who might be happy for the extra damage.