The Many-Angled Ones are a race or group of demonic-like extradimensional entities which were created by Grant Morrison and were the primary antagonists in his Zenith comic strips in the 2000 AD sci-fi comic magazine published by Fleetway Publications. The novel author Charles Stross would incorporate the Many-Angled Ones into his Laundry Files series, which combine several genres (Lovecraftian horror, science-fiction, and the spy thriller) mixed with workplace humor.
The divisions of the CIA and MI6 have no idea that they have been battling the Many-Angled Ones. They have been doing so since Alan Turing came up with a theory that with a computer you could warp reality and the Nazis used the Holocaust as the fuel to summon them to Earth, though fortunately the Nazis were defeated before enough human lives were sacrificed. In one reality, they were successful and the entity that came through drained all heat from around it and decades later the universe was about to die.
The two primary espionage groups dealing with the paranormal are "The Laundry" (Britain) and "The Black Chamber" (United States), the latter of which is secretly controlled by the Many-Angled Ones. Among the eldritch entities in this multiverse are Nyarlathotep and Cthulhu. The moment the stars align, the Many-Angled Ones are able to filter through the universe's walls, which the Laundry was forced to confront recently.