Blood Thirst
Blood Thirst is a combative ability in Dishonored 2 that lets players build up Adrenaline while fighting against enemies. As you take down and parry enemies, you’ll gain Adrenaline. Once you’ve reached the limit, the screen darkens, and you’ll be able to instantly kill your next enemy.
Blood Thirst gets even better when you pick up the Adrenaline Burst perk. This allows your Adrenaline to build up to a certain level even when you’re not engaged in combat. This means that when you do get into a fight, you can trigger the auto-kill much quickly, and end your fights swiftly. Greater Blood Thirst is a nice perk to have as well, but considering its cost, I’d hold off on picking it up until you’ve gotten the more important High Chaos abilities like Vitality and Reflexes. The perk grants you two auto-kills instead of one. It’s a nice bonus to have, but not entirely necessary for High Chaos players.