I feel the need to point out that Rai dying (spoiler) was already determined from the start. He spend 800 years trying to heal from a fatal wound and barely managed to heal himself. Not to mention he continues to use up what little time and life he has left for the people around him. Because he wants them to be safe. He doesn't mind dying for them, as a Noblesse that was going to be his inevitable end and he knew this. People who argue that Rai shouldn't have needed to die, obviously didn't understand the premise of the story.
Noblesse