Brooklyn nine nine - The winter soldier

I don't think there is any Brooklyn nine nine fan fics so I thought about if a super soldier was in the show. Even better someone who has connections to the underworld.

I think the winter soldier would be great because it would be a way for Bucky to clear his name.

Anyways, this could be expanded on with different characters such as John wick or even an ex-cop who is making their return.