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.
I'm not sure specifically what 'blox love story' is about without more context. It could be a love story within a game or a fictional world related to 'blox' which might involve characters in a romantic relationship and their adventures together.
I'm not sure specifically what the 'blox watch story' is about without more context. It could be a story related to a Blox watch, perhaps about its creation, the adventures of someone who owns it, or a fictional story set in a world where Blox watches play a significant role.
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.
Since I don't know the specific 'blox love story', I can't say for sure who the main characters are. They could be two young blox - like creatures or maybe human - like characters within a Blox - themed environment.