While discussing the unexpected team-ups in Avengers: Infinity War, Marvel Studios president and producer Kevin Feige talks Thanos and Cate Blanchett's Hela from Thor: Ragnarok.
A theory online amongst fans suggests Hela may be the MCU version of Death, Thanos' mistress in the comics. Vulture notes Kevin Feige wouldn't confirm nor deny Cate Blanchett's Hela is Death or whether she will appear in Avengers: Infinity War, but offered she has a great part in Thor: Ragnarok.
"I would be psyched if I were you," Feige said. "Put it this way: Her part is wrapped [in Thor: Ragnarok], and we haven't done any effects yet. Even without any effects at all â€” I'm talking dots on her costume, and green screen â€” it's amazing."
Regarding Death in the comics, the Infinity Gauntlet graphic novel that inspired the MCU movies saw Thanos so devoted to Death, that he went out and acquired the Infinity Gems (Infinity Stones in the movies) to impress her (to say the least). Feige offered the motivations for Thanos in Avengers: Infinity War may be different than the comics.
"Anything is possible," Feige said. "But knowledge of the comics can be both beneficial to fans anticipating things, and also misleading. So you'll have to see."
Regarding what we'll see from Thanos, a recent Marvel employee did confirm Thanos will kick some tail in Avengers: Infinity War, so at least that part fits in line with the Jim Starlin comics.
"Thor: Ragnarok" hammers home November 3, 2017; "The Avengers: Infinity War" has a May 4, 2018 release starring Josh Brolin as the Mad Titan Thanos.