Steve (for what ever reason you want) is a vampire. He has lived a long life,he has killed,he has tried to protect.The years however are lonely.He finds a baby/child Bucky and decides to raise him.

Bonus if Steve keeps Bucky addicted to his blood through out the years (all vampires are slightly mad after all)

Bonus Bonus if they become lovers when Bucky is older.

Can be as calm or as creepy as you want.