MTL - Super Dragon Slaughtering System - Chapter 4430 Break the prison

This is a story that follows the courtship between a stone from Hell and a god from Heaven that begins in the underworld and spans for three lifetimes in the mortal realm.

Crossing into the world of Naruto, and acquiring the One Piece system, with all the powers of the world of One Piece, swordsmanship, devil fruit, domineering.

-Do you think that your fire is very powerful? I have the burning fruit.

-Do you think that your thunder is very powerful? I have a thundering fruit.

-Do you think that your otter is very powerful? I have the frozen fruit.

-Did you said you want to die? Don’t worry, I also have a nickname: Death Doctor.

- Description from Novelupdates

After crossing over into a world of magic, Dean Bruce was mistaken for a powerful sorcerer. Though he initially intended to sternly refuse the beautiful woman’s request to become her mentor, she offered him far too much to say no!Completely clueless about magic, Dean Bruce had no choice but to make up spells on the spot. However, when he saw the astonishing power unleashed by the beautiful woman after chanting his random incantations, he was stunned.The spells he had carelessly invented… could they really comprehend magic and even forbidden spells?As Dean Bruce ascended to the pinnacle of magical prowess and became the Archmage, he candidly answered a reporter's question during an interview with the Alliance: “ never understood magic. I just made up a few incantations, that's all.”People were in awe of him—this, they believed, was the true humility of a Grand Archmage!

A story about a traveler who crossed into a parallel universe, relying on his Proficiency ability to continuously grind experience and become stronger.