Progenitor Regeneration

Progenitor Regeneration is one of Kokkan's many Tailed Beast Medical Ninjutsu. It allows him to repair, as well as grow new skin and muscle tissue. To use he releases his tailed beast chakra at a point were he is damaged, he then forces and combines it with the cell at the location. This causes the undamaged cells to rapidly begin to produce more cell, which he is able to manipulate into new tissue. Combining this with his Shikotsumyaku, allows him to regrow limbs. Kokkan stated that this just cannot be used to repair damage done to him by the bijuu chakra, and the greater the damage, the longer it takes to him.