The Sun of Neptune

Death, or Thantos, from my book, is some sort of a different character from all the others, gods, and demi-gods. Thantos, is the spirit, or god, of death. He is Hades’s (god of the underworld) first lieutenant, or personal assistant. What I do not understand about Death, is why he doesn’t help Percy, Frank, and Hazel, in fighting against the spirits.
Frank, almost killed himself by burning away his life-line, and yet Death does not help him. I think that Death is a very laid back person, that might not care much about all the quests and prophecies. He probably doesn’t feel like he is part of that world, that he is just death, and that he does not need to be part of all the other stuff. Though, he surprises me because he doesn’t take Hazel’s life, somebody who cheated death, when death was tied up. I think it is because she is a daughter of Hades, death’s boss.
I think that maybe Death is not a god, that maybe Death is just Death, an immortal being, but really nobody with exceptional power.
Death is a very weird character, that really does not seem to be necessary. I think Death should just be an Idea, not a character.