Here's what I think is gonna happen so we know after getting the yams yama no bmi he was looking for a paramecia fruit he was gonna kill luffy for his we litter here him saying he is going to go kill luffy that's why ace says you can't do that that's my brother now in in Impel Down arc at the end when luffy is gonna fight black beard and Jinbe tells him not to black beard says you brother saved you which means ace saved him by causing Marine ford allowing him to kill whitebeard and get his paramecia. So if black beard somehow learns of Luffys fruit he will kill him for it
