Black Receiver

Black receivers can be created and used by those who possess the Rinnegan. They act as high-frequency chakra demodulators, allowing users to transmit their chakra into these receivers and by extension those into whom the receivers have been embedded. Chakra can be transmitted across vast distances, though for best results the user should be nearby and at a high elevation. Black receivers disintegrate if their creator is killed or incapacitated.

Origin
The source and exact method of creation of black receivers is unclear, having been seen produced through various means:
 * Rinnegan wielders are able to generate them from their own bodies, usually their hands.
 * Nagato's Six Paths of Pain can also generate them from their bodies.
 * Madara Uchiha drew a black receiver from Hashirama's artificial body, calling the receiver his will in physical form.
 * Black receivers have protruded from the Demonic Statue of the Outer Path's midsection, on one occasion piercing Nagato's back and draining his life force. He was afterwards able to control the Demonic Statue.
 * As the Ten-Tails' jinchūriki, Obito Uchiha seemingly converts his Truth-Seeking Balls into black receivers in order to perform the Six Red Yang Formation.
 * Black receivers have sprouted from Obito's prosthetic limbs on several occasions, typically while his actions are being controlled by others.

Usage
Users can modify black receivers' size and shape to fit the situation. The most frequently seen usage has been as part of the Six Paths of Pain, where the user embeds corpses with chakra receivers in order to reanimate and take full control of the body, performing jutsu through it and allowing the user to see what the body sees. These black receivers are fashioned to look like body piercings. Creatures summoned through the Animal Path also have these body piercings, suggesting a similar manner of control. The receivers used on Obito Uchiha's Six Paths of Pain double as a means of temporarily binding the tailed beasts to the bodies, granting them access to the beasts' chakra.

Black receivers can be employed offensively, wielded from the hands similar to swords. By stabbing a target with these receivers the user can transmit their chakra into them, hindering their movements if pierced with only one receiver and completely paralyzing them if pierced with multiple. Simple contact with the receivers apparently incurs the same debilitations, an effect only other Rinnegan users are immune to. If a user is able to create a strong enough transmission into a target then they can control the target's movements. This all can run a risk to the user if they are using the Six Paths of Pain, as sensors can trace the black receivers they have been pierced with back to the user.

Obito is shown employing black receivers as projectiles, ejecting them from Kamui's dimension to pierce and pin targets. He can then transmit the Demonic Statue Chains into the receivers, strengthening the binding.

Trivia

 * When Obito's Six Paths of Pain enter Tailed Beast Mode, the black receivers relocate. For example, before transforming Rōshi's receiver in his chest, whereas after transforming it is in the neck.
 * In Naruto Shippūden: Shinobi Rumble, Pain's Black Needle Stab temporarily reverses the controls of those stabbed with black receivers.