MTL - Those Sweet Times - Chapter 10 Helping the heart

Rainer, an amateur arcanist and college student, sought to create a new spell far surpassing the magic of the few he inherited from his grandfather. Yet the interference of an unknown event during the casting of his spell led him to be thrown through space and time.

A man reincarnates in the body of a boy who suffered a tragedy, only to realize that he is in the world of My Hero Academia. What's even stranger is that his quirk seems to have the abilities of Nen and Haki.

“A qualified gunner should have enough firepower coverage.”

“So my battery has a diameter of three thousand meters, which is very reasonable.”

After a grand fireworks, Chen Jiang looked at the shocked eyes of the passers-by around him and said seriously.

…

When all races were thrown into a world and started to fight, a world with the theme of survival began.

- Description from novelbuddy

A slime randomly falls into existence. Sapient and born with the ability to recreate parts of the things it preys upon, the highly confused drop of primordial soup decides that the only real thing it can do is become the being at the top of the food chain. A task of longevity in the leaves of the Omniverse.