One Piece: Kaido's adopted son, opening the Eight Gates

Lin En starts traveling through the world of pirates. Good news: he obtains the top-level domineering color at the beginning. Bad news: he is a baby!
Just as he was about to be bitten by a poisonous snake, Kaido committed suicide by falling from a high altitude and saved Lin En.
Lin En simply released his Conqueror's Haki to attract Kaido's attention, joined the Beast Pirates, and was adopted as Kaido's son!
After surviving for 100 days, he obtained the Dragon Ball [Air Dance]. Lin En could fly without using the power of the fruit, shocking everyone in the Beast Group!
After surviving for one year, he obtained the Hokage's [Eight Gates of Dunjia], opened seven gates and repelled the Navy Vice Admiral, shocking the Navy!
After surviving for three years, he obtained the [Magic Light Killing Cannon], and even the Four Emperors couldn't stop it with just one finger!
That's not all, there's also [Susanoo], [Chibaku Tensei], [Kamiu], [Teleport], and so on...
Kaido: "I have been sitting on the throne of the Four Emperors for too long. It's boring. Im, come down. I want to sit on the throne of the King of the World with my adopted son, Lin En!"