Glitch of Death Achievement Guide

 Use TimeFart Glitch to cause a status-effected enemy to lose their turn and die at turn’s end.

Time rollback is a quest event, you need to debuff an enemy with the every-turn-damaging effect (bleeding\shock\sickness). When the last turn remains for him and he uses it, roll the time back – the enemy will die.

P.S: You may debuff with all 3 effects just to make sure.