Eight Gates Released Formation

This is a heightened state that is achieved by opening all Eight Gates. The user opens their body's eighth gate by puncturing themselves just above the heart, causing a bloody steam (resembling a flaming red aura) to start emanating from their pores, hair, and eyebrows. While all of the Eight Gates are open, the user's heart pumps at maximum power, granting them power a hundred times greater than they are usually capable of, far beyond that of the Five Kage. Their body will continue to heat up until it's been cooked from the inside-out, inevitably killing the user by reducing them to ash. A powerful healing technique, however, can be used to save the user from death.

Might Duy, the "Eternal Genin", was able to fight the Seven Ninja Swordsmen of the Mist and (in the anime) kill four of them. Might Guy is able to gradually overwhelm Madara Uchiha – the Ten-Tails' jinchūriki at the time – earning him comparisons to Hashirama Senju.

Trivia

 * After using this technique, Might Guy was saved from death when Naruto Uzumaki used Yin–Yang Release to revitalise Guy's heart. However, the damage done to his leg from using Night Guy leaves him wheelchair-bound for the rest of his life. Despite the handicap, Kakashi Hiden, Konoha Shinden, and the Boruto anime all show Guy continuing his life as a ninja as best as he can.
 * In Naruto Shippūden the Movie: Bonds, Shinnō claims that his Body Revival Technique, combined with Dark Chakra, allows him to open all eight gates without any drawbacks.