Misnomer is a
member of the NYPD Pyschic and Superhuman Investigation and Operations Division a supervillain that has come to power during the second wave of superhumans. No one in the Department knows his real name, due to his ability to change his identity, so instead they call him John Doe.
Misnomer has the ability to take on the appearance of anyone he chooses, including any superpowers they might possess. There is one caveat to this; he has to have killed the person to take on their identity. Also, this does not mask his psychic energy, nor does it change its frequency, therefor a superhuman with a powerful enough psychic awareness would still be able to tell it was him.