Who he is: The Other
His power: Other than being able to communicate telepathically (via beaming another’s consciousness to where he is), it’s unclear what powers The Other possesses, as he never has a chance to do anything much beyond glide menacingly.
His story: The Other is Thanos’ servant, which is how we first meet him in The Avengers. He gives Loki the scepter, and waits for him to acquire the Tesseract in order to open the portal between Earth and the Chitauri army (and does a little telepathic threatening of Loki when it starts taking a little too long). By the film’s end, he’s explained to Thanos the failure of Loki and the Chitauri and warns him that challenging humankind is as good as courting death. (Foreshadowing!)
He next appears in Guardians Of The Galaxy, where he acts as the intermediary between Thanos and Ronan The Accuser, who have made an agreement wherein Ronan acquires the orb containing an infinity stone for Thanos, and in exchange, Thanos will destroy the planet Xandar. However, after learning that Gamora has stolen the orb and betrayed Ronan, The Other summons Ronan (along with Thanos’ other daughter, Nebula) and chastises him, until Ronan loses his temper and kills The Other by snapping his neck with his concussive weapon. Which is how we learned never to pick a fight with a Kree.
Played by: Alexis Denisof
Currently, The Other is: R.I.P.
Where will we see him next? That’s probably it for the little guy.