After Eating the Dark Fruit, You Will Be Summoned by the Fallen Saint.

Zhao Yuan traveled to another world. In this world, as long as you obtain the ability of the Devil Fruit and become an SSS-level powerhouse, you can gain supreme status. He decided to swallow the Dark Fruit, control more powerful power, and make the strong men around the world bow their heads. Finally, he found the dark fruit. Suddenly, a call came from the distant starry sky. ... I am Cheng Ningfu, living in the world of Kyushu. The world of Kyushu is facing an invasion from another world. The situation is very critical and there is an immediate danger of annihilation. I decided to turn into darkness, become a fallen saint, open the treasure house of the fallen emperor, and save this crisis. Unfortunately, the other world is too powerful and I still can't resist it. Before I died, the system told me that I could sacrifice my life to summon the guardian of Kyushu. I decided to sacrifice my life in exchange for peace in the world of Kyushu. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.