Azrael

Azrael was the first necrotist, infamous even millennia after his death for committing many grizzly, macabre and horrific acts of murder, genocide and planetary destruction in pursuit of his idea of art.

Biography
Little is known for certain about Azrael's species, although he was apparently humanoid. According to the stories, Azrael hailed from a world where immortality had been achieved and was a fact of life; as his first "statement," Azrael turned his people's science against them and brought them to an agonising destruction. Azrael then went on to spread his idea of art as something that could only be achieved through death and agony, by slaughtering "countless" worlds over the course of three centuries. Among all his atrocities committed in the name of 'art,' Azrael's "masterpiece" was the Wasting Wall; Azrael constructed it by burning out the minds and souls of an entire species of peaceful giants and fusing their bodies into one giant structure in space. Azrael also chose to wear a mask carved from the skull of the last Magellan Emperor. Circa 8000 B.C., Azrael was finally captured and was sentenced to execution. But on his execution block, just before his death, Azrael proclaimed, "Death is my ally."

Although Azrael was indeed dead, his mask contained his skills and memories, and would grant them to whomever wore the mask and was a worthy enough murderer to be Azrael's successor; it was commented that Azrael hadn't cheated death but had "made a deal with her." Azrael's real, original mask eventually fell into the hands of Danny Fisher in the Obsidian Mainframe, until Danny was killed by Annabel Lake when he'd attempted to murder all of Cornucopia. (The Blood of Azrael'')