The main character is summoned, I don't remember what was going on before he was summoned, and placed in a kind of competition with other beings who were summoned. All the other summoned people were from worlds that had magic. They were each given a dungeon and were allowed to place them where they wanted on a new world. All of the other participants placed theirs in areas of high magical power while the main character didn't know anything and had his start in an underground volcano so he could evolve his creatures naturally. While all of the other participants had actual magical creatures he was only beginning to have multi-cellular organisms. At the part I had stopped reading he had found out the volcano he was inside of had become sapient from all of the magic power inside of it.