The Irish actor would join a star-studded cast that includes Angelina Jolie as Thena, Richard Madden as Ikaris, Salma Hayek as Ajak, Brian Tyree Henry as Phastos, Kumail Nanjiani as Kingo, Lauren Ridloff as Makkari, Don Lee as Gilgamesh, and Lia McHugh as Sprite.
It was also learned Captain Marvel star Gemma Chan, who played blue-skinned Kree warrior Minn-Erva, is also engaged in discussions for a role in Eternals. It's not yet known if Chan would reprise her Captain Marvel role or take on a new character.
"It's about this group of incredible immortals, but through their journey, we really get to explore what it means to be human and humanity on our time on this planet," director Chloé Zhao said at San Diego Comic-Con in July, where the project was officially announced by Marvel Studios president Kevin Feige.
Explaining its cosmic cast of characters, Madden described the Eternals as "a race of immortal aliens sent to Earth by the Celestials to protect humankind from the Deviants," humanoid creatures who are among the Elder Races and the Eternals' primary foes.
"Everything after [Avengers: Endgame] and after Spider-Man: Far From Home will be different and be unique, as we try to make every film. But seeing returning characters is certainly something we're gonna do and want to do. But also introducing characters that the majority of the world has never heard of, much like Guardians [of the Galaxy], much like Avengers before we made Avengers. And there are lots of them," Feige previously told Collider.
"Eternals are one group, but we like the idea of introducing an ensemble, doing an ensemble movie from the start, as opposed to building up as we did with the first Avengers. More like Guardians, not tonally, but in terms of introducing a new group of people."
Feige then noted Eternals would borrow heavily from the works of creator Jack Kirby.0comments
"Jack Kirby did an immense, amazing epic with Eternals that spans tens of thousands of years, and that's also something we haven't really done, which is why that among many other things post-Endgame, we find appealing," Feige said.
The Eternals opens November 6, 2020.