The Chakra Disruption Blades are blades made from the same material as the chakra receivers used by Nagato. They originated from the black rod in the Demonic Statue of the Outer Path's abdomen. Pain creates the blades as needed from both arms of any Path, with no apparent limit to their length. Pain can also detach the blade from the arms when requiring to use several of them, or to be thrown as harpoons.[1]
The effect of being stabbed with the blade.
These blades disrupt the chakra of its victim, rendering them incapable of moving. When a victim is stabbed by the blades, the Rinnegan appears in their mind, suggesting that Nagato has some degree of influence over them, similar to how he controls the Six Paths. The blades are very sharp, as they were able to pierce the skin of Sage Mode users. The blades themselves are hard enough to break scalpels though it is shown that they too can be broken with enough strength. In the anime, they are shown to have a red reflection.
Nagato, due to being immobile, can fire his chakra disruption blades from his mechanical seat, which then allows him to control the victims like one of the paths due to the close proximity between each other. Naruto was able to resist Nagato's influence with the help of both Sage Mode and the Nine-Tails chakra.
Other Media
In Naruto Shippūden: Shinobi Rumble, Pain has a technique called "Black Needle Stab" (黒針突, Kokushintō), in which he simply dashes at the opponent and stabs them with the blade, causing their controls to become temporarily reversed; an enhanced "Full Throttle" version is also available, called "Black Needle Stab: Destructive Flash" (黒針突・滅閃, Kokushintō: Metsusen). As no specific name was given for these weapons in the manga, this may imply that they are officially known as "Black Needles" (黒針, Kokushin).
Trivia
- The main difference between this and the Chakra Receivers is that receivers begin transmitting chakra to his Six Paths of Pain when they are activated.[2] Nagato also seemingly went to some lengths to retrieve them.[3][4] While these are used in battle and only transmits chakra when Nagato wants.[5]