You Know the Origin Bullet? The God of War Returns

The protagonist, Yifan, has a golden finger: six abilities belonging to his future self, combined with his own ability to make guns on Earth. Yifan is the reincarnation of a God of War, but in his previous life, he was killed in a siege by powerful beings. Reborn on Earth, he uses Origin Bullets to blow the heads off powerful beings across countless worlds. In the end, he roams the Myriad Worlds unchallenged and takes part in the grand battle of geniuses from every world.