I was just rereading Dressrosa arc, what if the Drill Kick Sai achieved during the final fight was actually Conquerers Haki imbued into his kick? When he landed the kick on G there was Blue Lightning and the ground shattered..
I would further argue that the fact that Don Chinjao used to battle prime Garp, who was a well known CoC puncher in his days so them clashing as know CoC, would solidify this assumption…
All in all
Sai achieved a level which we haven’t truly discovered during that time and by looking back with the knowledge we have now, its safe to say that Sai possesses CoC and imbues his kicks with it…
Another prediction, the way on how Oda portrayed Doffy, he would fit the ranks of a Holy Knight tremendously well!!! The last time we saw him, he was saying something along the lines of,, they are coming after me‘‘
So what if those who came down to Imple Down were actually Holy Knights freeing Doffy and offering him a spot as a Knight of God!
why Doffy makes sense:
-he is basically IMU jr by plotting everything like Imu..
-he sees everyone below him..
-he is CoC user, the only ability the Knights lack!
-Imu was trying to recruit another chained man on Elbaph, so why not try recruiting another chained outlaw?
-Oda has his way on reintroducing old foes in an updated version, Lucci from CP9 to CP0 with an awakened Zoan, Crocodile from an weakass Shichibukai to a Yonko caliber mind, so why not bring back a fan favourite, Mista Cruelty Doflamingo!!??
Hence my prediction, Doffy is getting a promotion and will be a member of the Holy Knights! Since Imu is about to lose some of then on Elbaph, he will be in need of backup and Doffy is one of its kind to fulfill that spot!!