The Night Guy is a forbidden taijutsu of the highest level that takes the shape of a dragon. It can be performed by those who have opened all Eight Gates, and is Might Guy's strongest attack.
When Guy initiates the technique, he emits a huge amount of chakra. After gathering all of this chakra around his body — forming a flickering dragon-like aura — he dashes forward at such an extreme speed that the space (空間, kūkan) within the immediate vicinity of the technique is distorted, allowing him to bypass his target's defences. Guy then deals an immensely powerful kick which carries such force that it is capable of obliterating the target's body, as well as shattering the bones in Guy's own leg. Being the most powerful of all Eight Gates attacks, it is also the most taxing on the body as it left Guy on the brink of death; Guy's body slowly turned to ash, crumbling from the immense discharge of his chakra.