From Destinypedia, the Destiny wiki
Overload Minotaurs are elite Minotaur units belonging to the Vex with enhanced ability regeneration. Once a target is spotted, the Minotaur will attempt to narrow the distance between the enemy, rapidly teleporting and occasionally shooting along the way, before striking them with its melee. After this, the Minotaur will near-instantly regain this rage and charge it's foes once again. To prevent this and allow some time for damage, a Guardian must use Overload Rounds, which will pull the Minotaur out of it's unwarranted rage and provide some time for damage while it's staggered before it gets back up to continue it's wrath.
List of Appearances