peer is a notorious assassin that travels across universes to fulfill assassination tasks for an extremely high price. He has the ability to teleport behind most people and kill them in one strike, so many victims have been killed by him when they least expected it. Furthermore, he quickly teleports away after most strikes he has deemed to be effective, so few people know who his victims were killed by.
Many humans are not able to match the speed of his teleportations or defend against his killing strikes, but some people have defeated him in combat, namely Combaticus and Dr. Promise. In particular, his teleportation ability is limited, and he can only teleport so many times in a short period before he tires out.
peer is reputed to have the ability to influence people to do things, an ability known as "peer pressure." While not true mind control or hypnotism, peer uses subtle tricks of the mind to persuade the listener.