One Piece: At Eight, I Snatched the Empress and Took Her Cultivating

[One Piece + Cultivation] [Lighthearted + Power Fantasy] Also known as "A Cultivator in One Piece, Leading the Cultivation Craze." The story takes place shortly after Roger's execution, and is half pirate story, half original.

On the day he turned eight, Ike was watching Roger's execution at the Sabaody Archipelago when he fell and startled the Celestial Dragons. He was then locked away on Impel Down's sixth level. Hell was empty, and the devils were in the human world! Fortunately, fate gave him a cultivation System through sign-ins, and he swore to overthrow this oppressive world.

He signed in at Impel Down, awakened the Divine Prison-Suppressing Body, and fought his way out!

He signed in at the palace on Amazon Lily and took eight-year-old Hancock out to sea to cultivate. From then on, the two grew up together as childhood sweethearts~

He signed in at Mary Geoise and received a blessed cave abode: Imu, it's time for you to make room!

He signed in at Ohara and withstood the Buster Call head-on, sending all the cannon fire back at the Marines. The Marine warships were instead destroyed by the Buster Call!

He signed in at Water 7 and received the Void Crossing Tribulation Ship: My ship is the greatest in the world, and I won't back down even against the Ancient Weapon Uranus!

"Shanks, I can tell you're blessed with extraordinary bones. Want to cultivate with me?~"

The young red-haired man hurriedly offered him a cigarette. "Captain Ike, you're too kind. Count me in!"

"Mihawk, isn't it boring to train with an ordinary sword? Want to learn to fly on a sword? I'll teach you until you've mastered it~"

Not long afterward, a young man named Kaido sought Ike out. "Ike, I heard you're strong. I challenge you!"

After losing, Kaido clung to Ike's leg. "Captain, didn't you say you'd take me to cultivate if I lost?"

Years later, Ike asked the straw-hatted boy from Foosha Village: "Luffy, what's your dream?"

Luffy answered with a serious expression: "I'm going to become the Cultivation King!"