The origin of Charybdis is deeply rooted in Greek myth. Legend has it that she once offended Zeus in some way. Her punishment was to become this menacing force in the sea. She resided in a narrow strait. Her whirlpool was so strong that Odysseus had to face the danger when he was on his journey. The story of Charybdis serves as a warning about the perils of the sea and the wrath of the gods in ancient Greek beliefs.
The story of Scylla and Charybdis often symbolizes the unavoidable perils and difficult choices one faces in life. It represents extreme dangers from which escape seems nearly impossible.
The plot involves Rimuru's journey from being a rather weak (initially) slime to becoming a very powerful being. He meets many interesting characters. For example, there are the goblins he befriends early on. Rimuru helps them improve their living conditions. As the story progresses, he also has to deal with the threat of other more powerful monsters and even some human kingdoms that view his growing power with suspicion. In general, it's a story full of adventure, growth, and the forging of relationships in a magical and dangerous world.
Charybdis was once a beautiful nymph. However, her fate took a turn when she angered Zeus. It's said that she was involved in some sort of conflict or disobedience. Zeus, in his might, decided to turn her into a terrifying sea monster. As a monster, she became a symbol of the dangerous and unpredictable nature of the sea. Her whirlpool was not only a physical threat but also a representation of the chaos that could befall those who challenged the gods. Sailors dreaded passing by the area where she lurked.
The main character is Rimuru Tempest. He is a slime who has unique powers and a great deal of charisma. Another important character is Veldora, the storm dragon who befriends Rimuru. There is also Shizu, a human who has an impact on Rimuru's early development. And then there are characters like Benimaru, a powerful ogre who becomes one of Rimuru's loyal followers.