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.
Makima's fate in the manga is quite complex and involves a series of dramatic events. She faces powerful opponents and has her own agenda that leads to significant developments.
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.