The Melting Pot of All Things: I Can Dismantle and Fuse All Things

I don't know how many years ago, the "wall of the sky" shattered, and wild beasts from other worlds poured in like a tide. Humanity was forced to retreat to seven huge "floating holy cities". In order to survive, human beings awakened the "Spirit Sea" and learned to capture the remnant souls of wild beasts to make the "Source Soul Seal", and gained power through fusion. However, there is an iron law in traditional fusion techniques: sources from the same source merge, and sources from different sources repel each other. Those who forcibly fuse source souls with different attributes will easily suffer backlash and die. Until the protagonist discovers that deep in his soul is an artifact from ancient civilization, the "Furnace of All Things," which can forcibly dismantle, purify, and reorganize the soul of all things in defiance of the rules.