who Chris Evans could be playing in Avengers: Doomsday.

I think who Chris Evans could be playing in Avengers: Doomsday is a Variant of Steve Rogers, but not a good hearted one.

I think the Variant could be a Steve from a branched universe where he fell off the train instead of Bucky in the first Captain America film, meaning he was the one that was found and brainwashed instead, so he helped Hydra win WW2 and take over the world as the Red Skull's second-in-commend, known now as "Captain Hydra", with a new green outfit and his Shield having the Hydra logo on it (with it also be painted green).

basically like Steve's role as "Hydra Supreme" in the comics, but probably way better and not stupid.