Last Divinity: The Advent Of Dreams - Chapter 20: Breached

Before going to college, an ordinary high school student went to celebrate and got drunk. When he woke up, he found himself in a completely different world. There was a big sect, the approaching sect entrance examination, a slum where his body’s previous owner lived, and a shared memory about a missing young girl.

When he got tangled in a fight with a few punks in this different world, he fell off a cliff and miraculously found himself still alive, with two more voices ringing inside his head. They were Sword Master and Saber Master. In the company of them, he continued to find out more about this whole new world. He took the sect entrance examination, entered the sect, met a strange man in black, and even participated in a major competition of the sect to have a chance to win over his peers!
In this whole new world, he was born again and got to explore the fantastic martial world!

- Description from Novelupdates

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

In the Dragon Abyss Empire, nestled within Clear Water Town, young Jiaang Lin awakens from a brutal beating by his cousin Jiaang Ren, only to discover he has been reborn into his younger self. Once a mocked disciple with blocked meridians, Jiaang Lin had risen to greatness in his past life as a prodigious warrior and Pill Saint. Now, with a second chance, he vows to protect his loved ones and conquer his enemies. How will Jiaang Lin change his destiny and ascend to the pinnacle of martial prowess once more?

At a young age, I became a thousand-year-old bastard.

Ding! Congratulations to the host, you have obtained the phagocytosis synthesis evolution system.

An earth dragon was found in front, devouring synthetic evolution, the earth dragon tortoise.

From then on, my wonderful career began…

- Description from novelbuddy