Advancement at this stage is also triggered by an accumulation of power, once the sacred artists core is filled to bursting it can be pushed even further to wash the body in madra and reforge it as an Iron Body. However, Sacred Artists must also push their madra channels outward from their core into every extremity of their body. Failing to do this cripples their future advancement and they will likely be unable to reach High gold without amazing luck, this form of Iron body is known as a flawed Iron body. After expanding all their channels a sacred artist can advance without worrying about damaging their future advancement and this will earn them a mundane Iron body. Finally, after both the accumulation of power and spreading of madra channels sacred artists can earn specialized Iron bodies called perfect Iron bodies that grant the artist special powers.