Can someone explain to me the ending of Guilty Crown? I read some threads related to Shu case, for example that he took all the voids and illness of each people to save them but then Inori in some way she took them and die instead of Shu. And after that Shu becomes blind because Inori was like that before she dies?

I am not sure..
During episode 22 after Shu defeats Gai and both he and Mana crystalize, Shu then uses both his original King power and Gai's power to absorb every single void and Apocalypse Virus remaining on the planet. After this action Shu becomes fully crystalized and has a vision of Inori offering him the Guilty Crown and Shu accepts. By this acceptance of the crown Shu and Inori switch places. A trade happens and Inori receives all of Shu's illness and he receives hers. ref(Guilty Crown Wiki)