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.
You can try searching on some popular fanfiction websites like Archive of Our Own (AO3). It has a vast collection of fanfictions from various fandoms, and there's a good chance you'll find ones related to 'Izuku has Sukuna' there.
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.