Rimuru explores the omniverse.

Chapter 1: The Tempest Federation

With the end of the Tenma wars (the holy war), the Cardinal world moved into a new time. Our hero, the Great Demon Lord Rimuru Tempest, stood at the centre of this change. With his otherworldly knowledge, the King of Tempest had completely changed the transportation, magic research, healing, and many other fields. But he had begun to separate himself from the lives of ordinary people. A spiritual being lives longer, and by becoming the ultimate spirit of Chaos, Rimuru had made himself immortal. Turn Null was the name of the power that Rimuru used. But the gods were afraid of this power, which they knew by a different name. "Chaos". The Tempest Federation did well, and Rimuru was very happy to see this. 

Rimuru had revived his past self, Mikami Satoru, and had left the hospital immediately. Was this the plan of Veldanava to find himself a successor or was it by pure chance that he had attained this godly status? 'I shall never know yet I am grateful.' Rimuru thought to himself. However as he roamed around Japan, he looked towards a shop of japanese culture. But what he found astonished him. "Ciel isn't this?" Rimuru asked himself and he could see Ciel analyzing the book that he had found.

<<Analysis of the novel: 'That Time I got Reincarnated As A Slime' has been completed. Indeed this is written on the life of Master. The Cause is predicted to be an Information Gathering Unique Skill possessed by the author Fuse. He has represented the information that he has gained subconsciously in the form of a novel.>> Ciel concluded and I was shocked. The entire world knew of my life yet none knew that Rimuru Tempest was a real entity except the residents of the Cardinal World. 'Ciel, if the cardinal world could exist as a novel. Are you implying that there are many other such world?' Rimuru asked Ciel.

<<Yes. Chances of probable worlds existing is 90 percent. According to Information derived from Akashic Records, we are a part of Veldanava's Creation: Tensura as Fuse has deemed it. Other Creators may exist and Master has surpassed Veldanava in power and hence travel to these worlds is an easy task for master who rules over space and time.>> However Rimuru wasn't shocked by what Ciel said. A man who can teleport from the end of space and Time and survive in absolute nothingness, could be capable of anything and it was then, that he had started to sense multiple eyes on him. 'Ciel who are they?' Rimuru asked and he could clearly see Ciel analyzing.

<<Information indicates, they are the Gods of Earth. Master would have known them as Amaterasu - The Goddess of the Sun, Susanoo - God of the Storm, Tsukuyomi - Goddess of the Moon, The Creator - Brahma, The Sustainer - Vishnu and The Destroyer - Shiva, The Monkey King - Sun Wukong, The Supreme Lord - Buddha and the Jade Emperor of Haneul. Do you wish to Interact with them?>> However, Rimuru used <<Absolute Teleportation>> to teleport to a new world. <<Location: Japan, Further information required for analysis of Universe.>>