Avatar: Mage of All Elements - Chapter 72

A mysterious natural phenomenon caused the Earth to be plunged into darkness. The world turned into an endless bloody chaos and mankind is on the brink of extinction…

“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

Leon transmigrated and became a lab rat for Hydra. But he ended up awakening the sign-in system.[Ding, sign-in reward: Glint-Glint Fruit(Pika Pika no Mi).]He starts by destroying the Hydra Base.He accumulated some time and got himself another reward![Ding! Get the sign-in reward: Sun Breathing Technique.]

Ron finds himself reborn in the world of One Piece, stranded on a remote island in the East Blue. But he's not just any ordinary child—he’s bonded to a mysterious sign-in system that grants him powers with every new location he visits.At his first sign-in, he unlocks the legendary Sun Breathing Technique, along with a boost to his vitality. From Shitmotsuki Village to Skypiea, Enies Lobby to Marineford, Ron travels the world, collecting extraordinary rewards that make him a force to be reckoned with. The Raikiri, one of the 21 Great Grade Swords, Armament Haki, Observation Haki, and more fall into his hands.As Ron steps onto the battlefield of Marineford during the legendary Summit War, the mightiest warriors—Four Emperors and Marine Admirals alike—pause, stunned by his presence. But Ron merely waves them off, “Don’t mind me. I’m just passing through.”Join Ron on his journey across the Grand Line as he signs in at iconic locations, growing stronger with every step. This is not just an adventure—it’s a legend in the making.