A very small number of particularly powerful Conqueror’s Haki users, stated to only be a “handful” by Kaidou, are able to “infuse” their body and weapons with their conquering spirit in a way that is very similar to Busoshoku Haki, greatly augmenting the power of their attacks. So far, Roger, Whitebeard, Kaidou, Luffy, Big Mom, and Yamato have been seen infusing Conqueror’s Haki.
So how can we determine which of them has a better Conqueror’s Haki level? Simple answer Oda has already shown us through panels.
In Chapter 1010 Luffy managed to coat his attack with Conqueror’s Haki but that time we didn’t know how strong his Advanced Conqueror’s was.
In chapter 1011 the sky above Onigashima was fully cover with clouds. But Luffy didnt manage to split it.
In chapter 1011 Luffy and Kaido clashed but it didn’t even affect the sky that much because Luffy’s Advanced Conqueror’s Haki was not that strong to split the sky.
We can see Luffy’s Conqueror’s Haki just only affected the nearest cloud area. It didnt affect the vast cloud which was way above from Onigashima.
Same in Chapter 1016, the rooftop was full of clouds.
Same thing happened when Yamato clashed with Kaido. The first panel in page 13 of Chapter 1016 has shown that the sky was covered with clouds but when Yamato and Kaido clashed in page 14 even Yamato didn’t manage to split the sky.
That means both Yamato and Luffy in Chapter 1011 were at the same level in Conqueror’s Haki strength that time, which was not even comparable to a Yonko.
Now the next stage Oda has shown about how strong every Yonko’s Cnqueror’s Haki strength is by showing us sky splitting moment:
Both Whitebeard and Shanks’ Haki were so powerful that managed to create heavy impact on the sky, that’s why even the heavens split up.
Same with Big Mom and Kaido and with the last clash between Luffy and Kaido. Oda has clearly shown us Yonko’s Haki capability. Only Yonko tier Conqueror’s Haki strength can split the sky.
ONLY Whitebeard and Roger’s Conqueror’s Haki strenght was even greater than the Yonko’s.
Roger vs Whitebeard Conquero’s Haki clash was not a typical Yonko clash. It was more powerful than a Yonko clash. It didn’t split the sky. It just totally destroyed the sky area.
The impact was so great that even vaporized the clouds. Their Conqueror’s Haki impact sent their crew mate flying and ships were hardly able to stay in their docking position. This shit we didn’t even see from any Yonko when they clashed with each other.
*Theory by Roronoa_D_Luffy1010