10Monkey D. Luffy
The Captain of the Strawhat Pirates, Luffy is the man known as the Fifth Yonko of the Sea. With a bounty of 1.5 billion, Luffy is already a fearsome pirate. When compared to Kaido, Luffy is, in no way, an equal to him yet. However, Luffy aims to take down
Kaido at Wano Country, and when he says something, he certainly does it.
Whether he'll be stronger than Kaido or not is a completely different question, but we're certain that Luffy will defeat Kaido, one way or the other. To take him down, Luffy has been honing his Haki at Udon Prison for several days.