During Matt's days in FBI, he obsessively sought to find and expose the Illuminati Society, which he believed to be controlling much of the world behind the scenes. Unbeknownst to him, his partner in FBI, Martin Hacker, was actually a member of the society who had been partnered with him in order to keep him on mere wild goose chases. Matt's obsession with the Illuminati eventually got him fired from the FBI.
Matt later became a detective at the 23rd Precinct in Manhattan. He was partnered with Elisa Maza shortly after she had recovered after a near-death experience of being shot with her own gun. Elisa was initially rather dismissive towards Matt but eventually came to recognize him as a valuable ally. She, however, never revealed to him that she was housing a clan of gargoyles in the Clock Tower above the police station. Matt became suspicious about the existence of gargoyles after several gargoyle sightings during the clan's conflicts.
Matt continued to pursue the Illuminati while working for the NYPD, but due to still getting information from his old partner Hacker, only ran into dead ends, one of which almost got him and Elisa killed by Tony and Dominic Dracon's gang. Eventually, Matt managed to track down the senior Illuminatus Mace Malone, who revealed the existence of the Manhattan Clan to Matt and offered him a place in the Illuminati Society in exchange for bringing them a gargoyle. Matt forced a confession about the clan from Elisa and convinced Goliath to accompany him to the Hotel Cabal. However, to ensure Goliath's safety, Matt first gave him a key given to him by Mace to navigate through the hotel's traps. When Mace attempted to kill Goliath and prevent him from escaping, Matt stopped him, earning Goliath's trust, but apparently forfeiting his chance to join the Illuminati in the process.
Soon after, Martin Hacker revealed himself to Matt as an Illuminatus, approached Matt, and granted him a place in the Illuminati anyway, claiming that he had fulfilled his end of the bargain.
When the Hunters exposed the Manhattan Clan to the public, Matt was made head of the Gargoyle Task Force. Matt did not believe the world was ready for an inter-species confrontation and encouraged the other members of it not to "go all medieval" and hunt down gargoyles and instead prevent panic. Hacker, also a member of the Task Force, assured Matt that the Illuminati approved of this.
Matt was a part of the resistance against Xanatos' tyranny. He was disintegrated by Xanatos' Mutate troops, alongside Claw and Bronx. This, however, turned out to be an illusion created by Puck ("Future Tense").
- Matt Bluestone at Garg Wiki