In Naruto, every shinobi has a natural affinity for a certain nature transformation, which make up all of Ninjutsu and is heavily connected to Senjutsu. The five basic nature transformations are Fire, Lightning, Earth, Wind, and Water. Each of the Five Great Nations is named after these transformations as well as the Five Kage. Chidori and Amaterasu are powerful examples of lightning and fire nature transformations used throughout the series.
Outside of the five basic nature transformations that exist, Yin Release and Yang Release are typically used for techniques that do not have an element associated with it, like Nara Clan's Shadow Paralysis Jutsu or Medical Ninjutsu. Yin Release is the manipulation of a shinobi's spiritual energy, and Yang Release is the manipulation of a shinobi's life energy.
When combined together, both form Yin-Yang Release, the rarest and most powerful nature transformation in the series.
Note: This article contains spoilers for both Naruto and Boruto series.
The origins and uses of Yin-Yang Release in Naruto
Yin-Yang Release was first used by Hagoromo Otsutsuki, the Sage of Six Paths, when he combined his spiritual energy with his physical energy, the two basic components of chakra.
Hagoromo's most famous utilization of this release was the Creation of All Things Jutsu, where he created the Nine Tailed Beasts from the Ten-Tails' immense chakra. To do this, he first used Yin Release to create the beasts' bodies and then Yang Release to bring them to life, giving them consciousness and personalities.
During the battle against Kaguya, Hagoromo gave Naruto the ability to use Yin-Yang Release, who used this power to heal Might Guy after he opened all Eight Gates and created a new eye for Kakashi after he lost his Sharingan. Unfortunately, this healing ability is unable to overpower guaranteed-kill abilities, such as Kaguya's All-Killing Ash Bones.
Due to being the perfect combination of both aspects of chakra, Yin-Yang Release is also capable of nullifying the five basic nature techniques and the individual Yin Release and Yang Release.
This allows for the Jinchuriki of the Ten-Tails to be invincible to both ninjutsu and genjutsu, making taijutsu and senjutsu the only options to fight with. Might Guy took advantage of this fact, allowing his taijutsu prowess to shine in his fight against Madara.
Most powerful Yin-Yang Release Jutsus
1) Creation of All Things Jutsu
The most powerful reality altering Jutsu in the series, the Creation of All Things Jutsu is the most famous Yin-Yang Release Jutsu. Mentioned earlier, it was used by Hagoromo to split the Ten-Tails into the nine tailed beasts shown throughout the series.
This technique allows its users to manipulate both spiritual and physical energy to turn fantasy into reality. The Creation of All Things Jutsu is also a precursor to Izanagi, the most powerful Sharingan genjutsu. However, Izanagi uses both Yin Release and Yang Release separately, rather than Yin-Yang Release.
2) Six Paths - Chibaku Tensei
Also known as Six Paths Planetary Devastation, Six Paths - Chibaku Tensei is the most powerful sealing Jutsu in the series. This technique takes the Six Paths Yin and Yang Seals and perfectly combines their power to extract the chakra from an opponent's body and seal their Rinne Sharingan. This is the only known method to effectively seal Kaguya Otsutsuki.
This technique was first used by Hamura and Hagoromo to seal Kaguya before the events of the series. She was once again sealed when it was used by Naruto and Sasuke after her revival.
3) Expansive Truth Seeking Ball
The Expansive Truth Seeking Ball is one of Kaguya Otsutsuki's signature techniques and a very powerful Kekkei Mora. After absorbing the chakra from the God Tree, Kaguya used this technique in an attempt to destroy the entire Naruto universe and rebuild it from the ground up.
Since this technique is forever expanding, the world could easily have been destroyed. However, due to its Yin-Yang Release nature, the Expansive Truth Seeking Ball is immune to almost all attacks.