Cathulhu Online, MUNYA! - Chapter 427 Cathulhu’s World Is Harsh For Protagonists

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

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

Mortimer Zhu is an extremely unfortunate high school student who accidentally enrolls into an academy of a dubious nature, where it is the norm to jump in front of moving trains, get dismembered during orientation, and crushed by vindictive bouncing classrooms. Can he stay alive or will he die from the rigors of school? Why have evil spirits suddenly acquired a taste for his flesh?

- Description from Novelupdates

The teenager Long Ao, ten years of silence, was reduced from genius to waste, and was ridiculed and mocked.

Ten years of persistence, ten thousand failures, and finally won mysterious Dragon Seal.

With Primal Chaos Saint Body, cultivation invincible cultivation technique, refining Heaven and Earth, devouring endless stars, sweeping the wasteland! Ask the vast stars, who dares to fight me? Boundless Starry Sky, War God! …

- Description from Uukanshu