I'm not sure who exactly 'Iam Tongi' is. There may be many people with this name. Without more specific information, it's difficult to tell the life story.
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.
I'm not sure specifically which 'Iam all girls true story' you are referring to. There could be many stories with this title or something similar. It might be about the experiences, achievements, or challenges of a group of girls.