The Guardians' Throne - The First Magic Swordsman - Chapter 244 - In Ten Years

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

I woke up in my sleep, and a strange door appeared in my home…Behind every door is a strange world.

In the nightmare world, Jiang Cheng added the news from the strong man to the fat man, and he almost cried when he heard the latter, “If you die here, the whole family will stand upside down and bleed?”

“Is such that.”

“Then I don’t think you are too scared?” The fat man widened his eyes.

Jiang Cheng turned his head and said in a very formal tone: “Because I am an orphan.”

- Description from novelbuddy

One of the Conferred Martial Emperors, Gu Feiyang, passed away in the Tiandang Mountains and was reincarnated 15 years later as Li Yunxiao of the State of Tianshui, embarking on a heaven-defying journey against the innumerable geniuses of the time.

The nine levels of the Martial Art; the Divine Realms of the ten quarters. From then on, the whole world fell into chaos!

Protagonist travels between different anime worlds to right wrongs and uncover his reason for being along the way.