Scrapcode Horrors: Rise of the Dark Mechanicum | Warhammer 40K Lore

The Adeptus Mechanicus seethes with a hatred. Their former brothers,
now twisted into the abomination known as the Dark Mechanicum,
left Mars soaked in blood and ashes. This treachery left a wound on
the soul of the Omnissiah’s priesthood that festers to this day.