Fairy Tail Destiny - Chapter 168: Ch : Azuma

Born into a unique world where villages fight to gain power and control, the main character, Shi Hao, is a genius blessed by the heavens born under the poorest of conditions. His clan, however, has a mysterious past. To rise up and become the genius he is meant to be, the clan goes through every effort to aid his cultivation as they battle through fanatical monsters and engage in power struggles with other clans. His journey will bring him through unknown lands until he is able to become a person that can truly shake the world.

Han Yun was spoiled from childhood.

He survived past his emperor dad and crown prince elder brother, and became an emperor.

He didn’t know how to govern the country, but he was lucky—there was a Grand Preceptor who “assisted” him, spoiling him even more than his father did.

After just a few years, this puppet emperor died. When he awakened, he had transmigrated into the modern world, becoming a third-rate model struggling alone without any loving parents.

Just when he thought he had become a little cabbage that nobody wanted and no one would ever spoil him again, a certain ancient monster of a Grand Preceptor who had lived 1,000 years appeared again… and looked to be doing quite well for himself.

The utterly impoverished little emperor had tears in his eyes: “Beloved subject! Zhen (royal We) have missed you so much!”

Grand Preceptor: “Your Majesty, this minister has waited for you for a thousand years.”

- Description from Novelupdates

Crossing to One Piece world, he became Roger’s younger brother.

Kurt was born to a poor Baronetcy of Arnold. He was a genius pastry chef in the previous world.