With tier one Blood Thirsty, Corvo can execute fatality maneuvers on his enemies with adrenaline, and requires two runes to unlock. It only lasts a short period of time, so use it quickly.
With tier two Blood Thirsty, Corvo builds up adrenaline faster, and can perform a double attack which can be used against multiple enemies within a nearby range. The time-limit is also lengthened and grows faster with each kill.
|The Knife of Dunwall|
|The Brigmore Witches|