Guardian of the Vault

Main antagonist of Vault Map in a separate Arena to the map.

Behavior

Two rotating phases during this battle. Animate Guardian and Animate Weapon spawn in a group of four, two of each. This appears to occur without limit throughout the encounter.

Phase 1:
The boss will melee any sufficiently close taunt, otherwise the boss will roam the map.
Phase 2:
The boss will submerge into the ground, and cast a series of Delayed Blast patches randomly throughout the area.

Strategy

Focus fire the boss and kite/ignore the continuous summoning of Animated adds. Otherwise, you may be quickly overwhelmed.