The Essence Keeper is a tool for collecting souls or blood added by the Harken Scythe mod. The Essence Keeper and the Essence Vessel alike are fundamental to crafting with the mechanics. Upon creation, they may collect Souls or Blood garnered by using the Scythe and Glaive's power attacks, respectively. When storing 1+ blood or soul, they will rename into Bloodkeeper or Soulkeeper, respectively. They may store 20 souls or 40 blood, used in crafting Livingmetal and Biomass among other things. One should make sure they have plenty on them to scoop up any blood or souls left behind after battle.
One can drink the souls and blood. Blood, when consumed, grants 30 seconds of Speed, 4 seconds of Hunger, and 30 seconds of Strength IV to the player along with negative effects unless they are wearing Bloodweave. This makes drinking blood a very viable option in combat, provided one has enough food or the Bloodweave.
Souls have multiple outcomes that you must be cautious of. Souls will always give one Hunger for 15 seconds and the effects range from great to deadly. Among the positive effects are Invisibility, Instant Health (effectively making one invincible), Haste, Speed, Night Vision, Fire Resistance, and Resistance. However, they may also give any negative effect. Instant Damage is a possibility and a menace due to the fact that 4 hearts of damage are taken every second until it wears off. Soulweave robes cause only the positive effects to come into play, making soul consumption a viable tactic in combat so long as one has enough food. All effects last for 1:30 seconds from the consumption of one soul.
- Consuming multiple doses of Blood/Souls at a time is possible. For each dose consumed in succession, 10 seconds will be added onto the duration of the buffs/debuffs.