Goldslayer: Last Man Crafting

Eight billion people are put into an apocalypse game with no exit. Lu Ming wakes up in it with two talents, an all-knowing eye that shows him danger before it arrives and unlimited synthesis that lets him combine anything into anything else. He starts at the bottom floor. He cuts his way up through the Order Society, the lord of the machine city, and the Trickster, and collects twelve fragments of the Axis of Ten Thousand Worlds. Along the way he picks up Old Zhao and Su Xiao, and between them they work out what the game actually is. The Administrators who run it are harvesters, burning human beings as fuel to extend the lifespan of the universe. In the final fight Lu Ming gives up his system and his divinity, and with help from the souls of his parents he rewrites the laws of the universe.