The Aul, the Crystal King delve boss fight contains 8 Crystalline Cocoons around the arena. These cocoons will open and shoot homing projectiles if the player is near. During Aul’s throne phase, the Spectral Shield Charge can destroy the cocoons if they explode near them. At some point during this fight, Aul will clap his hands together, create Darkness, and spawn minions. In order to avoid the Darkness from stacking up, the player can either strategically use flares or hug the small flares that drop from some of the minions.
Spectral Shield Charge: Aul retreats upon his crystal throne in the center of the arena and fires a total of 6 spectral copies of himself. These clones shield charge towards the player with exploding steps and then explode on impact. The clones are fired one at a time in a slow rate of succession. The base duration for this attack is 10 seconds and deals 75% Cold Damage and 25% Physical Damage. These clones can open the Crystalline Cocoons by damaging them, but will trigger the Crystalline Barrage attack.
Aul, the Crystal King is a boss that can only appear inside The Crystal King’s Throne nodes within the Primeval Ruins biome, inside The Azurite Mine in Delve, at a depth of 130 or greater.