Trying to decide between a few character ideas:

Basilisk: some dude who will royally screw you over if his mask is removed.
Null: some person who is capable of deleting any information relating to them, including in peoples minds.
Mary Sue: a person capable of MANIPULATING information relating to them, if they have an entry in a database, for example, they can manipulate the database, if someone thinks about them, they can change how people think about them.
Cognitohazard: same as before, only the changes are uncontrolled.

Or a mad scientist who does mad science things.