Heretek

Heretek is the name given by the Adeptus Mechanicus to those tech-priests who turn their backs on the teachings and strictures of the Cult Mechanicus in pursuit of usually dark and forbidden technologies linked to the power of the Warp and the Ruinous Powers of Chaos.
Hereteks value the pursuit of knowledge, of any knowledge, at all costs, regardless of the consequences to themselves or to others and even at the peril of their own souls.
Many Hereteks are loosely connected to the Dark Mechanicum, those members of the ancient Priesthood of Mars who turned their backs upon the Emperor of Mankind during the Horus Heresy and the Schism of Mars and swore to serve the Warmaster Horus and the Dark Gods in return for technological advancements denied them by the Emperor for the safety of Mankind.
Others, however, pursue the dark path of tech-heresy completely on their own, forging their own roads to damnation independent of any direct connection to Chaos or the Dark Mechanicum, though still wholly in violation of the strictures of the Cult of the Machine God.
Hereteks discovered or captured by the Mechanicus are either executed outright or have all of their cybernetic implants painfully removed and their organic remains transformed into a mindless servitor as penance for their tech-heresy.

"The path of the Omnissiah has left humanity dithering in the darkness, incapable of advancing on the paths of knowledge. Embracing the Warp reveals technology that the primitives on Mars could never dream of wielding." — Magos Caine of the Five-Fold Path

Starting skills:
Deceive or Inquiry, Forbidden Lore (pick one), Medicae or Security, Tech-Use, Trade (pick one)
Starting Talents:
Weapon Training (Solid Projectile)
Starting Equipment:
Stub revolver with 2 extra clips of Expander bullets or Man- Stopper rounds, 1 web grenade, combi-tool, flak cloak, filtration plugs, 1 dose of de-tox, dataslate, stablight
Background Bonus:
Master of Hidden Lores: When a Heretek makes a Tech-Use test to comprehend, use, repair, or modify an unfamiliar device, he gains a +20 bonus if he has one or more relevant Forbidden Lore skill specialisations at Rank 1 (Known) or higher. Hereteks also start with Mechanicus Implants.
Background Aptitude:
Finesse or Tech