The Life Steal ability allows Evan to extract the power of Core Evolvers and condense it into a consumable item that he can use himself or give to other people.
The person who uses the consumable item created by the Life Steal ability will receive all the powers of the person whose power was extracted.
Normally, the power of this ability depends on Evan's own rank.
For example, his current rank is mid-level Rank Two.
With his current rank, using the full power of Life Steal ability, he can extract the power of mid-level Rank Three Core Evolvers.
However, if he wants to extract the power of a higher-level Core Evolver, it would be very difficult for him to do so without increasing the rank of his core.
But the Blood Bullet skill of Carnage is a special skill that allows him to increase the ability of his bloodline by sacrificing his blood essence.