Mortimer was not a rich man. Born to a poor family, he took up the work of a coroner and mortician rather quickly from the local mortician. Pleased to do no more than that, he had no expectations when he came across a hidden away painting in the back of the mortician's home. Painted by a Sphinx (a sect of mages who paint awakenings), he was immediately awakened into the path of the Moros.
Originally a Guardian of the Veil, he fell astray when he dipped into consuming his own memories to seal the knowledge away. His job was to find information no one should have, and destroy it, both in the physical sense, and within his own mind. Years of doing this took a toll on him, and he began to forget the core aspects of his own identity. It wasn't long before he lost his awareness of his own magic, and he became a soft-spoken man, obsessed with death, but with no true ties to it any longer. So full of the ghosts and memories of other people he had stolen, he could not tell them from himself.
During the events of Slasher I, he engaged in Brute (and then Mask) like levels of violence. It did not take him long to become a pure murderer, worried only with causing death. He lost his identity, and went to kill his gravedigger, Tombstone, but was beaten to it by the police, who had gone to investigate his funeral home and gotten into a gunfight with Tombstone and his adopted son, Jack. Going to the morgue, he removed Tombstone's face and wore it proudly until his re-awakening. Eventually captured by the hard work of VASCU's best, he awakened in the transport helicopter and killed everyone on board, which during the crash, included himself. A hanging spell of his own devise went off, draining the life from the world around him and rejuvenating him. Free of the ghosts and of other people's memories, he awakened to his old power once more. He then murdered almost all the members of the original SOUP. (One was hiding in a trunk, another got stabbed by the Rev.)
During the events of Mage II, Bones was a super powered god. Still a true believing Christian, Bones sought out God, for now he had godlike powers as well. He thought this would mean that he could truly find Him. Mages were convening to stop Bones, who was rousing ancient ghosts and slaying mages by the dozens to find the knowledge of God's location. Unable to stop him, only one of the mages that had gathered to stand against him survived, Clementine. Bones spoke with the eldest ghosts, and gained a mask of Nyarlathotep from the near-deity himself.
During the events of Hunter, Bones was put to an end through the summoning of Devil Jones, a demonic ghost with power to rival his own. While Devil Jones peeled off his mask of Nyarlathotep, a gun enchanted by a Death Arch-Mage shot and killed Bones, once and for all.