Among the main characters besides Rimuru are Gobta. He is a goblin who is rather comical at times but also shows growth throughout the story. Then there is Diablo, a very powerful demon who becomes Rimuru's subordinate. His power and knowledge contribute to Rimuru's rise in the world of the novel. There are also other characters like Milim, a dragonoid with a child - like personality who has her own impact on the overall plot.
Milim Nava is an interesting character. She is a powerful Demon Lord with a child - like personality. She often gets involved in Rimuru's adventures in unexpected ways. Then there's Shion. She is a hobgoblin with great loyalty to Rimuru. Her over - the - top reactions and her growth in strength and character add a lot of fun to the story.
There's Veldora. He's a powerful dragon sealed within Rimuru's stomach at first. His presence has a great impact on Rimuru's growth and the story. Then there's Shion, a strong ogre who becomes one of Rimuru's loyal followers. She's known for her combat abilities. Also, Benimaru, a kijin, is an important character. He plays a key role in the development of Tempest.
Most BSD light novels often have complex characters. Since they are based on literary figures, they bring in the depth and complexity of those original personas. For example, a character might have the same traits as a famous writer but with a unique twist for the BSD universe.
Rimuru is very strong in the manga. He starts off with some unique abilities and keeps getting stronger through different events and encounters. His strength is not just physical but also in his strategic thinking and leadership skills.