I've heard stories and legends of Tradesmen. "People" who offer you something good, in return you give them your Soul. They come out of no where or you can summon them. I'm just curious, are they real?
People, I don't know, but other entities I think yes. They do not trade your soul, but your energy through reincarnation cycle, and reincarnation after incarnation, the soul loses its own energy, till it may never incarnate as a human again .
This is in simple words what I was told, I don't know how true it is