Let’s start with these panels:
When Luffy used Conqueror’s Haki in Udon Prison, we saw that japanese letter right in Luffy’s panel; the same thing happened when Zoro was about to use Asura to cut Kaido.
Now about Sanji, he also got the same japanese letter, which is hinted about Conqueror’s Haki, while he is in Bath House from Flower Capital when fighting X-Drake and Hawkins. Is that Conqueror’s Haki too? Maybe yes and maybe not.
Now, let’s see these panels:
Back in Sabaody Archipelago, we meet Silvers Rayleigh which is the Vice Captain/Right Hand Man of The Pirate King, Gol D. Roger
The first time he used Conqueror’s Haki, only Luffy, Zoro, Sanji, and Usopp got an highlighted/single panel about them reacting to Rayleigh’s Conqueror’s Haki. In that panels, Luffy, Zoro, Sanji aren’t even afraid and we even see Sanji’s eye looks like that.
Recently, we got a leak about the Covers of Volumes 99, 100 and 101. One Piece Volume 100 Cover features Luffy, Zoro, Sanji, Ace, and Yamato.
Among these 5 characters there are 3 Conqueror’s Haki users. That means only Yamato and Sanji aren’t confirmed as Conqueror’s Haki users.
In Chapter 1016, as Yamato and Kaido clash a big lightning is produced.
Now my assumption is that Yamato might also have Conqueror’s Haki.
So if Yamato is confirmed to be a Conqueror’s Haki users too, that means Sanji is the only one who doesn’t have Conqueror’s Haki in that cover. If Sanji doesn’t have Conqueror’s Haki in future, why Oda willingly put him alongside these 4 of Conqueror’s Haki Users?
Finally, Zoro and Sanji shared the same panel reaction to Luffy Conqueror’s Haki in Fish-Man Island:
I think Sanji will end up having Conqueror’s Haki too, Oda gave us so freaking many hints about that!
What do you think?