Yin–Yang Release

The techniques make simultaneous use of Yin Release and Yang Release. Yin relates to one's spiritual energy and Yang relates to one's physical energy and it's necessary to utilise both of these in order to mould chakra for ninjutsu. According to Yamato, the manipulation of Yin and Yang is the source of non-elemental techniques such as the Shadow Imitation Technique, Multi-Size Technique, medical ninjutsu, genjutsu, etc.

Usage
Sage of the Six Paths had such a mastery over the Yin–Yang Release that he used Yin to create form from nothing, and then used Yang to breath life into what he has created. He could even make them come to life. According to Tobi, the Sage's ability was called, which he employed to create the tailed beasts out of the chakra from the Ten-Tails. The technique Izanagi is based on this ability.

Madara Uchiha has implied that Yin–Yang Release was involved in the creation of White Zetsu and his clone siblings.

Obito Uchiha, after becoming the jinchūriki of Ten-Tails, uses Yin-Yang Release perfectly through black orbs which destroys anything it touch including ninjutsu.

Trivia

 * Hiruzen stated that this nature transformation is beyond Kekkei Genkai or Kekkei Tōta.