9. Ikaris Betrays The Eternals (And Flies Into The Sun) - Eternals
It was admittedly genuinely surprising that the Eternals' leader Ajak (Salma Hayek) was killed off in the movie's first act, having been ambushed by the Deviant leader Kro (Bill Skarsgård).
But later in the film, it's revealed that Ajak was actually set up by her fellow Eternal Ikaris (Richard Madden), who pushed her into the Deviant trap after she attempted to speak up to the other Eternals about Arishem's plot to destroy Earth.
It wasn't that difficult to guess that one of the Eternals might be a turncoat, and honestly, there was no more obvious choice than Ikaris, but what really cemented this twist as clunky and underwhelming was the outcome.
At the end of the movie, a guilt-riddled Ikaris flies into the Sun, committing suicide.
Given that it's made abundantly clear earlier in the film that the myth of Iracus, who flew too close to the sun, was actually styled on Ikaris, his demise is a rather cringe-inducing attempt at cleverness that ultimately feels like it was written by a grade-schooler.