The Genesis Loop is a unique Boss item that has a chance to be dropped by the Wandering Vagrant when it spawns as the Teleporter boss.
The blast has a short charging period, during which the player can seek for the optimal place to explode and damage the highest amount of enemies. Old War Stealthkits make this easier, as both items are triggered by taking extensive damage.
The blast also triggers if the cooldown is completed while the character still has under 25% health left, even if they have not been damaged recently.
The charging time of the blast lowers the more attack speed you have.