When Satoru Mikami—in the newly acquired body of a slime—meets Veldora, he discovers that he’s unusual in more ways than one. Firstly, Veldora observes that most slimes are low-ranked monsters and aren’t even able to think, which already helps Satoru stand out as a self-aware slime. Secondly, Veldora informs Satoru that he’s not the only person from other worlds to have been brought to this one, but he is the only person that has been reincarnated into this world.

Rimuru Tempest’s signature ability is his “Predator Skill” which allows him to swallow anything and learn about its properties. When he tests this unique ability on a snake, he discovers that he can not only transform into a snake but also use its abilities. The other handy trick the “Predator Skill” allows him to do is to store some of the stuff he swallows. If Rimuru stores the right combination of ingredients, he can even convert it into something like a potion.

Before he even became a slime, Rimuru was a chronic helper. The day of his death as Satoru Mikami, he was about to give advice to one of his juniors about marriage. It was his decision to sacrifice himself so that his junior and his junior’s girlfriend were not stabbed that led to his death. As Rimuru Tempest, he’s already vowed to free a dragon of his seal, help a small goblin village against a pack of direwolves, and made a ton of longswords for a blacksmith. If you’re in need of help, you won’t need to try too hard to get Rimuru on your side.

Caught between a desire to help his new friend Veldora and to explore the world for other people like him, Rimuru decides to bring Veldora along with him. Seeing as Veldora is sealed, Rimuru swallows the entire seal and stores Veldora inside of him. His hope is that the “Predator Skill” will eventually decipher how to get through the seal. Having eaten the ancient dragon, Rimuru has altered the nearby ecosystem and begun exuding the overwhelming aura of Veldora. His swallowing of Veldora has set off a chain reaction in this fantasy world that may actually turn out for the best.

Although Rimuru is far from the sort of person to go looking for a fight, he’s been constantly embroiled in them from the start of the series. While he was in the cave, Rimuru found himself fending off all sorts of creatures. When he left the cave, he worked for a town of goblins to defend against a pack of direwolves. He doesn’t back down from the threat of the pack and carefully helps the goblins build defenses. It becomes clear enough that while Rimuru is far from bloodthirsty, his enemies are still better off not provoking him because he’ll do what he feels is necessary for those he wants to help.