Sukuna does die in the manga. The way it happens is quite dramatic and ties in with many other elements of the story, adding depth and tension to the overall narrative.
No. Ryomen Sukuna is a fictional character from Japanese mythology and modern manga/anime. He doesn't have a basis in a true historical event or person.
Nope. Ryomen Sukuna has no basis in reality. It's a product of the creative minds of the writers and illustrators who designed a captivating fictional character for the enjoyment of the audience.
A cold smile or a hot haha was a kind of opposite smile. A cold smile was a smile that contained contempt, ridicule, helplessness, anger, and so on, while a hot haha was a kind of passionate smile. The cold smile and warm laughter were fake and pretentious, making people's hair stand on end. The word 'narrow-minded' was used to describe a person who was careless and big-hearted. Sometimes, it also implied that he was simple-minded. This word was usually used to describe a person's attitude of letting things that were related to their own interests develop in a bad direction.
In the manga, Sukuna doesn't possess all 20 fingers. There are specific story arcs and events where his finger count changes based on the plot developments.
In the manga, Sukuna does acquire all his fingers over the course of the story. This is a significant plot development that has major implications for the storyline and character dynamics.