Now we know why Base Luffy never used Advanced Amament Haki internal destruction on Ulti and Page One, he would have one shot them killing them permanently.
Luffy One shot Pag
Oda was restricting Luffy from using it, as it has been proven to be extremely effective on Zoans, as proven by Garp pre timeskip taking out Marco while the Admirals failed to do that without seastone.