Black Gear

Black Gears are evil devices used by Devimon to control good Digimon and turn them evil. The digimon under their influence can be set free by destroying the gear or by a Digidestined's Digivice, which expells evil. These are only featured in Digimon Adventure, but the theme is revisited in Digimon Adventure 02 via Dark Rings, Dark Spirals, and Dark Spores.

Instances of Use

 * Meramon was the first known Digimon to be attacked by a Black Gear. It was destroyed when Biyomon digivolved to Birdramon and fought him.
 * Andromon, Monzaemon, Unimon, Frigimon, Mojyamon, and Centarumon were all under the influence of the Black Gears, but were set free by the Digidestined.
 * When Devimon broke apart File Island to separate the Digidestined, the children were able to piece the island back together by damaging the Black Gears within it.
 * Leomon was infected by Devimon with the Touch of Evil, and was later powered up by seven more black gears. The Digidestined managed use their Digivices to drive all the Black Gears out and return him to normal.
 * During his final battle against the Digidestined, Devimon absorbed several Black Gears to make him larger and stronger.

Legacy
Although Devimon was destroyed, Black Gears continued to live on and digimon that were already under their influence continued to be evil. Whamon and Drimogemon were both under the influence of the gears, but were both freed by the Digidestined. Drimogemon was of particular interest as Devimon used him to guard the Digidestined's tags, possibly preparing for the event of his death. It was also the last time a Black Gear was seen.

The Black Gears may have also inspired the Dark Rings and Dark Spirals used by the Digimon Emperor four years later, as they serve a very similar purpose.