The Academy's Barbarian - Chapter 4: To The Academy (2)

The world where the Hero and the Demon King continue to oppose each other. The grand magic from the Hero and the Demon King cross over worlds and exploded in the classroom of a certain high school.

The students who died in the explosion will be reincarnated in a different world. The protagonist, who had the lowest reputation in the class, was reincarnated into a spider. Nevertheless, she adapted quickly to the present condition with strong willpower.

This is a story of she who has become a spider trying whatever she can to live.

While returning home from a boring day of work, a black hole opened up in front of John and sucked him in. Before he was floating in the blackhole, a helmet latched on to him. "Uploading A.I under progress...Activating Survival Kit" A weird robotic sound appeared within the conscious of John and suddenly a white energy enveloped him... After opening his eyes, John noticed he was teleported to a whole new world. A world of magic and he was a user of a system. Arkon, the world John was brought too, was a medieval world which is 10 times bigger than earth. This new world held many new mysteries and this was the beginning of John's adventure. John will dominate and stir the world with his new system. Old technologies begone and use my advanced techys instead! Ha! you want to hold a politic, economical and military war with me? Sorry but my system is too broken for you all to counter.

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