Hunter's Grenade

Hunter's Grenade is a skill. Unlike most other skills, the Hunter's Grenade deals no damage nor affects the player. Instead, it only affects enemies with blueprints that you have not collected. It turns the affected enemy into an elite.

In order to gain a blueprint that you have not collected, you must first lower the elite's health to below 40%. Then you must use the Blueprint Extractor on the elite (which is dropped on the ground after you use the grenade) in order to gain a blueprint.

This item is unlocked from the Collector for 100 cells and can be found in The Prisoner's Cell behind a gold door, which can be unlocked for 7500 gold.