Talk:Challenges/@comment-40198082-20190718200800/@comment-68.113.138.220-20190823224016

For keyed up, I personally got that achievement by using MUL-T and getting the Ocular HUD and Disposable Missile Launcher. Since the missile's can crit you just use the Hud then missile launcher and shoot at the boss to finish him off if he's not already dead. I don't remember exactly when it happened, but it was within the first 3 stages, and I was on normal difficulty.