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.
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.
Pose isn't based on a true story. It's a fictional drama that explores various themes and characters through creative imagination. The plot and events are crafted by the writers to engage and captivate the audience.