I think Doflamingo's skill + Haki > Sanji's skill + Haki. Sanji isn't at that stage yet, hell if Law is having troubles against Doflamingo, Sanji is way out of the league there. Even Luffy will have troubles defeating Doflamingo if the time comes when they fight 1v1, he'll be defeated that's the final verdict we all know but it'll be a Lucci type fight I predict. I want Law to die, he's a overhyped overpowered character xD But I don't think that's gonna happen It'd still be pretty epic if he died. Maybe he's beaten to near death when Luffy saves the day, putting Law in an eternal debt to Luffy.