Naruto System in One Piece - Chapter 33

Chi Lang transmigrated to the Middle Ages as a third-rate magician in a third-rate magic academy. His magical aptitude is zero. But he has a good roommate.

His roommate is good-looking.

His roommate is good-natured.

His roommate helped him escape from danger several times.

His roommate never complains.

Chi Lang felt like he liked his roommate a little bit, and then his roommate helped him solve his ‘single’ problem.

It wasn’t until much later that he realized that his roommate was a remarkable figure.

——He was one of the demons sealed by the magician known as the “God of Magic”… And Chi Lang became the one who unlocked the seal of the Demon Lord.

- Description from Novelupdates

When an era came to an end, various forces set foot in cultivation to compete for immortality. A young boy who spent most of the time sleeping got lucky in the troubled times and became an unparalleled immortal who could cover the sky with a snap of fingers. Was he going to live forever?

- Description from Novelupdates

The world had started doomsday, and I struggled for a year, before I died under an enchanted beast’s claw. Heaven has given me another chance, back a day before the end happen. Will I be able to change my fate, and that of my loved ones? Now, I will start my journey on becoming the strongest on the planet that the Gods have changed into a game world.

Shaymon, the man who has achieved the apex of dark magic, is framed as being a Demon King and is killed.