Kinjutsu

are techniques that have been banned from being taught. This ban can have been put in place for any number of reasons, but kinjutsu can generally be put in either of two categories: Despite their being banned, the use of these techniques generally does not carry any consequences, except those brought on by the techniques themselves. However, their use is heavily frowned upon, especially those techniques that violate Nature. All kinjutsu are either A-rank, or S-rank.
 * 1) Techniques that do extreme harm to oneself (e.g. opening the Eight Gates, which will bring almost any user to the brink of death),
 * 2) Techniques that violate the Laws of Nature. (e.g. the Summoning: Impure World Resurrection, which resurrects the dead with a human sacrifice)