Diablo 4 Season 9, titled Sins of the Horadrim, shakes up the endgame boss experience in a major way. This season introduces changes to boss mechanics, loot tables, and progression systems tied to the new Boss Ladder. From the redesigned Astaroth encounter to the introduction of Belial and the Fell Council in Infernal Hordes, the game now emphasizes targeted farming and boss-specific loot more than ever before.

In this article, we'll break down the most important boss loot information you need for Season 9. Whether you're farming for Mythic Uniques, class-specific gear, or crafting materials, this guide will walk you through what to expect from Astaroth, Lair Bosses, Greater Lair Bosses, Horadric Strongroom mini-bosses, and more.

Astaroth – The Escalating Nightmare Boss

Astaroth is the primary boss introduced in Season 9 and serves as the final encounter of Escalating Nightmare Dungeons. Unlike previous encounters, Astaroth now features a second phase where he splits from his steed, turning the fight into a two-boss battle. If you kill the steed first, it can resurrect unless Astaroth is defeated quickly. This encounter is further complicated by Nightmare Dungeon affixes, adding unique modifiers to each run.

Astaroth's loot includes guaranteed drops such as Horadric Jewels, Resplendent Sparks, and Obductie. He also has a high chance to drop Mythic and regular Uniques, Ancestral gear, and Legendary Diablo IV items, making him a must-farm if you're pushing character power in Torment 4.

Lair Bosses – Core of the Boss Ladder

Lair Bosses form the foundation of Season 9's Boss Ladder system. These include familiar faces like Varshan, Grigoire, Lord Zir, Urivar, the Beast in the Ice, and more. These bosses require keys to summon and can sometimes trigger ambushes by Belial after their loot hoards are opened.

Each Lair Boss has a unique loot pool, with some offering exclusive Mythic Uniques or newly added class items. For instance, Grigoire can drop the Demonbinder mount cosmetic and Penitent Greaves, while Lord Zir is tied to drops like the Sanguivor, a new two-handed sword for Necromancers.

Summoning each boss typically requires completing specific activities and collecting 12 of a key material:

· Urivar requires Judicator's Masks from Kurast Undercity.

· Grigoire needs Living Steel from Helltides.

· Beast in the Ice demands Distilled Fear from high-tier Nightmare Dungeons.

· Echo of Varshan is summoned using Malignant Hearts from Tree of Whispers.

· Lord Zir uses Exquisite Blood, found during Helltide Blood Maiden events.

Notable Loot Highlights from Lair Bosses

Urivar's drop pool includes high-drop-rate Uniques like the Ring of the Ravenous and 100,000 Steps. Mythic Uniques such as The Grandfather, Harlequin Crest, and Melted Heart of Selig have a 4.5% drop chance. Cosmetic rewards are guaranteed after the first kill.

Grigoire features gear like Loyalty's Mantle, Rage of Harrogath, and Waxing Gibbous. His Demonbinder mount armor cosmetic is also a 100% drop.

The Beast in the Ice drops both high-value Uniques and the Skull Torch cosmetic. Players looking for Cold-based or Druid-specific gear will find this boss especially rewarding.

Echo of Varshan has a loot table that includes class-specific Uniques for Druids, Necromancers, Rogues, and Sorcerers. Notable drops include Airidah's Inexorable Will, Fields of Crimson, and Tal Rasha's Iridescent Loop.

Lord Zir's loot includes top-tier Barbarian weapons like Ramaladni's Magnum Opus and Druid armor like Bane of Ahjad-Den. Zir also drops the Diadem of the Ancient cosmetic helm.

Greater Lair Bosses – Advanced Boss Ladder Tier

To summon Greater Lair Bosses, players must use 3 Boss Lair Keys earned from defeating Initiate Lair Bosses. These bosses offer significantly better loot and more difficult encounters. They also have a chance to spawn Belial in an ambush, escalating the danger and reward.

Key Greater Lair Bosses include Duriel, Harbinger of Hatred, and Echo of Andariel.

Duriel, King of Maggots, is one of the top loot sources in the game. He has a 4.5% drop rate for Mythic Uniques and drops items like Azurewrath, Tempest Roar, and the exclusive Sunbird's Gorget. Players also receive the Smoldering Brimstone mount cosmetic for defeating him.

The Harbinger of Hatred drops similar loot to Duriel, sharing the high-value Mythic Unique pool and items like Scoundrel's Leathers and Flamescar.

Echo of Andariel has the same Mythic Unique drop chances and item pool as the Harbinger, with guaranteed cosmetics.

These bosses are all level 100 and require materials from Tier 4 versions of Lair Bosses to summon. For example, Harbinger requires Abhorrent Hearts from Urivar, while Andariel requires Pincushioned Dolls from the Beast in the Ice and Lord Zir.

Belial – Apex of the Boss Ladder

Belial is the top-tier boss introduced this season and is summoned using two Betrayer's Husks, which can drop during Ambush Encounters after defeating other bosses. Players must decide which Lair Boss's loot table they want Belial to pull from when opening his Hoard.

Defeating Belial guarantees an Ancestral Unique and offers the highest chance for Mythic Uniques in the game. If you're playing at a party, each additional member increases the odds of extra Unique drops. Belial is the most rewarding boss in terms of pure loot potential and offers an exclusive endgame challenge for coordinated groups.

Horadric Strongroom Mini-Bosses

Horadric Strongrooms now include faster mini-boss spawns (100 seconds instead of 2 minutes), higher monster density, and more intense ambushes. These mini-bosses are essentially dungeon bosses with a twist, as they are randomly chosen and modified. Players who fully attune the Strongroom gain access to significantly better rewards.

These encounters are great for farming crafting mats, Strongroom-specific items, and enhancing your overall gear progress while progressing Season 9 objectives.

Infernal Hordes and the Fell Council

The Infernal Hordes activity is a survival-style game mode where players fend off waves of increasingly difficult enemies to earn Burning Aether. The final wave ends with a fight against the Fell Council, which drops exclusive Uniques, Mythic Uniques, and class-specific weapons.

Each class has a best-in-slot Unique obtainable through this system:

· Barbarian: The Third Blade, Executioner's Fortress

· Druid: The Basilisk, Moonrage

· Necromancer: The Mortacrux, Shademist

· Rogue: The Umbracrux, True Sight

· Sorcerer: Vox Omnium, Winter Touch

Burning Aether can be spent on three types of reward chests—equipment, materials, or Diablo 4 gold. Farming Infernal Compasses through Nightmare Dungeons, Helltides, and Whispers of the Dead is the best way to access this content repeatedly.

World Bosses and Pinnacle Boss

World Bosses like Ashava and Avarice remain essential for materials like Exquisite Blood and Spoils Caches. They also drop Scattered Prisms and boss summon materials, making them a core part of your boss farming loop.

Finally, the Echo of Lilith remains the ultimate test of skill in Diablo 4. As the pinnacle boss, she drops the Resplendent Spark (on first kill), a unique mount, and a special title. While she's not part of the Boss Ladder, players still seek her out for prestige and endgame bragging rights.

Final Thoughts

Season 9's overhaul of the boss system in Diablo 4 is the biggest step toward an engaging, farmable endgame. Whether you're running Lair Bosses to chase Uniques or grinding Burning Aether in the Infernal Hordes, the loot opportunities are the best they've ever been. The addition of Belial, escalated difficulty tiers, and boss-specific gear pools gives players more control over how they build and optimize their characters.

If you're still pushing into Torment 4, Astaroth and the Lair Bosses are the best places to start. And once you've got the keys and the gear, the Greater Lair Bosses and Belial are waiting with the most coveted items in the game.