According to the writing duo behind “Eternals,” Ryan and Kaz Firpo, even when the film was in its earliest stages, they intended for Eros to play some kind of role. In fact, as Ryan told The Direct, on their board of roughly 40 Eternals to include, “Eros [was] definitely a card that went up on the board to be in the main movie.” However, as we now know, they never went in this direction with the character. Why? As they go on to explain, his presence would’ve complicated Ikaris and Sersi’s already strained romance.
“We really wanted to concentrate on Sersi and Ikaris’ love story,” reveals Ryan Firpo, reasoning that Ikaris’ presence made it difficult to work Eros in without them “stepping on each other’s toes.” Thankfully though, they found a way to squeeze the latter into the film in some capacity — a decision they made with the wider MCU in mind. Ryan refers to Eros as “the perfect coda character to introduce” as a result of his familial connection to Thanos, who still stands as the franchise’s biggest villain to date as Phase Four finds its footing.
It would have been nice to see more out of Eros in “Eternals,” but it’s safe to assume we haven’t seen the last of Harry Styles’ super-powered alter-ego on the big screen.