Power ON

After zoning into the raid, take the right-hand path toward the Vigilant Guardian. Just before the boss room, look to the right of the main walkway for a platform where the Depleted Automa is lying inactive.

Use a displacement ability to move the Depleted Automa into the boss room before pulling the Vigilant Guardian. Death Grip from a Blood Death Knight works reliably. Typhoon or Thunderstorm may also work. Alternatively, on Normal difficulty you can kill mobs close enough to the arena edge that the Depleted Automa gains power while still on its starting platform.

Pull the Vigilant Guardian and kill two Pre-Fabricated Sentries near the Depleted Automa to charge it. You can type /focus Depleted Automa to track its yellow power bar filling. Once fully powered, the Depleted Automa creates a large zone that reduces damage dealt to other adds.

Kill the Depleted Automa before the Exposed Core phase begins, as the AoE from Exposed Core can be lethal. On Normal difficulty, wait for an Exposed Core cast, exit the arena to the platform or jump into the water below, kill the Depleted Automa, then return to the arena before adds reset the fight. You have roughly 20 seconds during the cast window.

Once the Depleted Automa is dead, return to the arena and finish defeating the Vigilant Guardian. On Normal difficulty, the boss does not roll out until you throw the Unstable Cores at it, giving you time to return. A Demon Hunter can wall-jump or dash back onto the platform; other classes can use a Goblin Glider or a Demonic Circle set before leaving the arena.