Adam Warlock
At the end of Guardians of the Galaxy Vol. 2, the perfection-driven Ayesha reveals she has a pod where she’s creating the next step in evolution for the Sovereign race. She names the person in the pod Adam, which has since been confirmed as Adam Warlock.
In the comics, Warlock is a perfect specimen of super strength, durability, endurance, etc. Now imagine if at the start of Guardians of the Galaxy Vol. 3, Ayesha opens her pod expecting an Olympian God of a man and it turns out to be… Matt Smith.
Don’t get us wrong, Smith is attractive in an alien sort of way, but he’s far from what a lot of people would call a “perfect-looking physical specimen.” Delivering such a character swerve is exactly the sort of thing James Gunn would do and it would fit within the humor of the Guardians franchise. Although the character of Adam Warlock will never be as important on screen as he is in the comics (he’s vital in the Infinity Gauntlet arc), casting Smith in the role would be the closest thing to a consolation prize that we can think of.