Fan Casting Malcolm in Murder Mystery

This billionaire is Charles' uncle who also stole Charles' fiancee Suzi; the yacht trip is to celebrate Charles and Suzi's wedding. One of his prized possessions is a dagger given to their family by Marco Polo (or so the legend says). So naturally, Chekhov's Dagger is what is used to kill Charles the first night on the yacht — this is called Murder Mystery, after all. Everyone has a motive because right before he is murdered Malcolm reveals that he is leaving his entire fortune to Suzi. But he is killed before he and Suzi can sign the new will.