In Avengers: Infinity War Thanos briefly touches on his motives for collecting all the universe-altering gems. Thanos claims that his planet, Titan, was once filled with life, but overpopulation led to the destruction of his homeworld. The Mad Titan actually comes from a race called the Eternals. The Eternals were created by Celestials (such as Star-Lord's father, Ego) in the early stages of the universe. The Celestials experimented on early humans, and other early humanoid aliens across the universe. The result were super-powered beings called The Eternals. Beings who were experimented on, that turned out ugly and twisted, were sorted into a category called Deviants. The Eternals and Deviants battled for centuries, and their wars may have something to do with Thanos' planet meeting its doom.

As reported by IndieWireChinese director Chloé Zhao has been tapped to helm The Eternals movie. She will be the first non-white woman to direct a movie in the Marvel Cinematic Universe after twenty films. The Eternals will be an important part of the MCU after Avengers 4 hits theaters, and you can expect them to be teased in the film. According to Kevin Feige, the film will focus on Sersi, an Eternal who decides to live her unnaturally long life on Earth, running into famous historical figures along the way.