Thanatos

THE GUIDING DEATH
Greek/ Roman God of death
Born from the primordial entity Nyx, Thanatos is a mysterious figure that guides those who are about to die unexpectedly to the underworld. Some believe that he caused these deaths, some believe he simply showing unfortunate souls mercy, no one knows.
For some reason, Thanatos is aiding Luke in his quest to fulfil his promise to Pluto. He enlisted the help of the party to achieve this goal. While he isn't interacting with the party he is training Luke in Tartarus to master his powers. Why is a Reaper so willing to go out of his way to train a player?