The "Keplers" are the otherworldly beings who first came to earth. They were in search of gold and created humans to mine it for them. Once they had what the needed they left, but promised to one day return, and that once they did, they would play Endgame.
Kepler 22b is the otherworldly representative who communicates with the players throughout Endgame.
It is clearly from another world. He is at least seven and a half feet tall, thin with broad shoulders, long arms, long and flat feet, and skin white like mother-of-pearl. It has a long narrow head, and its facial features appear neither male nor female, with long platinum hair and thin eyes that are entirely black.
It wears a dark cloak with light points which are compared to stars, and white shoes that seem to shimmer.
Its voice is also neither male nor female, and is described as pleasant.
At the end of Endgame - The Calling, he appears on Shari Chopra's television as an odd but attractive Asian man with black hair parted down the middle. He has round eyes, full lips, a thin nose, and high cheeks, and wears a collard shirt which is open at the neck. His voice remains the same.
Kepler 22b can speak into the minds and read the minds of the players and teleport. It has the abilitiy to temporarily paralyze specific parts of the players' bodies, such as just their legs, as well as removing and giving the ability to speak quickly to the players. It also has and controls a disk of sorts that creates visual holograms and can send images straight to the Players' minds. It can also cause on Player to suddenly feel drastically cold.
He shows the ability to appear upon television under disguise.