Blizzard could easily integrate Elias using a material-based system, just like existing Lair Bosses. Imagine a new drop like "Shard of the Triune Ritual" or "Fallen Horadrim Remnant", earned by defeating Initiate-tier bosses. Collect or buy Diablo 4 materials, and Elias can be summoned as the third Greater-tier challenge.

Proposed Fight Structure

Phase 1 - Elias, Master of the Triune

A spell-slinging battle where Elias summons ritual spikes and homing blood sigils.
Cultist waves spawn periodically, pressuring players to manage adds.

Phase 2 - Arena Shift

Upon "defeat," Elias vanishes in a burst of blood magic.
Players chase him through a gauntlet filled with exploding runes and teleporting ambush enemies.
This adds dynamic pacing not currently seen in other Lair Boss fights.

Phase 3 - Elias, Fallen Horadrim

His rage-fueled final form takes center stage.
Fast-paced attacks, tri-directional blood waves, teleport spam, and illusory clones.
Duriel's relentless pressure meets Astaroth's chaotic spellwork-forcing players to adapt.

Fight Hooks and Flavor

No Lorath ally this time-Elias faces the player alone, amplifying the tension.
Difficulty scaling on par with Duriel, ensuring Elias feels like a legitimate Greater-tier gatekeeper.
Unique loot table, featuring Triune-themed caster gear or Necromancer-focused Diablo 4 Items like curse-enhancing staves and Diablo IV Items for sale blood-magic rings.