Fans got their first look at what he was capable of during this fight and, needless to say, he proved his strength by effortlessly taking out some very powerful next-generation pirates, such as Basil Hawkins, Urouge, X Drake, and even Scratchmen Apoo.

Source: https://gamerant.com/one-piece-kizaru-pika-pika-no-mi-explained/

This was confirmed to the fans shortly before the timeskip when X Drake met Scotch in combat on a winter island.

Source: https://gamerant.com/one-piece-yonko-most-territories-ranked/