A brother bond and a mate

It'a Vampire A/B/O Story. Devil fruit exists. When a unconscious person was found by the spade pirates, everyone is curious. Who is this person and where did he come from. Ace, Luffy, Sabo and OC (won't play a big role) are siblings with devil fruit powers. While Ace is stuck with his two younger siblings, Sabo is a revolutionary. They are 1/3 Vampire's. Main pair is MarcoxAce