User can create blades from blood.

Pros:
-user can manipulate blood
-user can create many different blades
-user can naturally use all types of blades
-user can make blood from all blood types, be it their own or from others
-user can solidify blood when it is made

Cons:
-user will quickly kill someone if not careful
-user may drain themselves too quickly
-user must consume blood of they reach their limit

Weakness: blood lust
User will drain a lot of people and make MANY blades