The Sleepers
Michael was surprised about two things. The first surprise was that the Primal disappeared just like that. Michael considered the Primal of the cosmos as beings overflowing with pride. It didn't feel like that at first glance, but Michael quickly noticed that there was more to the Primal than pride as well.
The Primal who'd attacked him had killed the Volcano God instantly while giving Michael a chance to survive. There was no doubt the Primal could have killed him with his first attack, but he didn't. He released the same attack he had used against the Volcano God and watched Michael survive and grow stronger from it.
Therefore, the Primal chose to transform their little bout into a game. In this game, the Primal tortured Michael by inflicting more serious injuries with every attack. It was almost like the Primal was trying to find out how to inflict the most lethal wound on Michael to discover what it would take to kill him.