Oh, a Black Hand. How Original.
The Marauders were a group of insane Mages who sought to create chaos in order to shake reality out of the Technocracy-imposed stasis they felt it suffered from.
Paradox Backlashes can take many forms. The most typical is a sort of explosion or other crude physical reaction as reality rejects an attempted alteration and snaps violently back into place. But sometimes the rebounding energy is channeled into the Mage's very soul and twists it beyond all recognition. Having spectacularly failed once to alter reality, they become obsessed with altering it as violently and dynamically as possible, as often as possible. This makes them incredibly dangerous. Some seek to create fantastical monsters, either unicorns and dragons of mythology, or twisted horrors of completely new and terrifying forms. Others seek to make alterations to reality easier by eliminating through acts of murder and genocide the unawakened majority whose unconscious beliefs hold reality in place.
When Gehenna erupted, the Marauders saw their chance, and took it. They violently lashed out at anyone and everyone within reach, killing millions before the Tech Infantry hunted them down and exterminated them. With Paradox much less powerful after Gehenna exposed Magick to the masses, very few mages have faced the sort of paradox backlash likely to turn them into a Marauder, but there have been several cases of Mages frustrated with the dystopic nature of reality who have voluntarily begun acting as if they were Marauders, or even trying to become Marauders through intentionally invoking paradox backlashes. Few who attempt this methodology survive, but those that do, can become very dangerous individuals indeed.