Summary
Power Absorption is the ability to absorb/steal others' powers/abilities. It grants the user new powers by stripping opponents off their abilities. Not only does it make the user stronger, it also makes the opponents weaker simultaneously by nullifying their powers.
It may have some limitations depending on the extent of the ability. Some power gains may be temporary, and the user might be overwhelmed or unable to fully control the absorbed powers. Some characters require preparation to absorb abilities and might not be able to do so actively during combat. Also, absorbing certain powers might fall under No Limits Fallacy.
Users
Various characters from Marvel