Why did Malcolm Merlin pick up Randal Savage's ashes in Arrow S04E08 and say You owe me one?

Malcolm Merlyn picked up Randal Savage's ashes in "Arrow" Season 4, Episode 8, as part of his plans to resurrect Savage, who is a significant figure in the DC Comics universe and has a longstanding connection to the character Vandal Savage. By saying "You owe me one," Malcolm implies that he is leveraging his connection with Savage to gain an advantage or fulfill a personal agenda, likely related to his ongoing schemes involving the League of Assassins and the larger struggle against the forces of darkness in Star City.