Armageddon Conclave

The Armageddon Conclave was an Inquisitor Conclave consisting of members of the Ordo Malleus. Named after the planet Armageddon, the Conclave's purpose was to prevent the summoning of another Daemon Primarch, to  avoid another catastrophe that befell Armageddon at the coming of Angron

Armageddon
The Conclave's founding dates back to 444.M41, when the Daemon Primarch of the World Eater Traitor Legion, Angron invaded the planet Armageddon. Though the Forces of Chaos lost, and the Primarch sent back to the Warp for a hundred years, it was a costly victory: Many Grey Knights and Space Wovles dead, millions of Imperial Citizens and Armageddon Steel Legion Guardsmen killed, and thousands more corrupted by Chaos. Some Inquisitors noted that this was only possible because the Chaos forces were led by a Primarch.

To state the obvious, Primarchs were the genetically-engineered transhuman sons of the Emperor of Mankind. Their powers easily surpassed that of any mortals and even their superhuman gene-sons, the Space Marines. Despite having turned their back against the Emperor more than 10,000 years ago, there is no denying that the living Traitor Primarchs are a powerful force, made even greater since they had ascended to Daemon Prince status. However, the Inquisition had underestimated their true might until the First War for Armageddon. Angron had single-handily wiped out numerous Grey Knights, powerful psykers and Adeptus Astartes who were bred to slay Daemons. If another Daemon Primarch ever emerged, would the Imperium be able to prevail? Worse, what would happen if more than one came into realspace?

These were thoughts of Lady Inquisitor Olea Silvolis of the Ordo Malleus. The Imperium could not risk another massive Chaos invasion, especially one led by a Daemon Primarch. Gathering like-minded individuals of her Ordo, Olea formed the Armageddon Conclave, named in honor of those who died on said planet. The Conclave's purpose was to investigate and halt preemptively any attempts to summon a Daemon Primarch, as well as other Daemon Princes or the ascension of a heretic into one.