Stream of the Grey Flames

Stream of the Grey Flames (灰色炎の流れ, Haiiro Homura no Nagare) is an original created by Nōsei which allows him to mimic fire natured techniques by utilizing the Yin Release to create a stream of grey chakra that takes the form of fire. This technique is performed much like fire techniques, with the user molding the Yin Chakra into the form of fire inside themselves before expelling a powerful burst of grey flames from their mouth. When met with a solid object this technique can either engulf the target or explode on contact with a powerful force. This difference in effect is dependent on how the user shapes the "flames." Furthermore the power of this technique is dependent upon the user's skill with this technique and the amount of chakra used. The heat of this technique is known to create dangerous burns, that would require immediate medical attention, but don't appear to have any other qualities.

While the chakra utilized by this technique is superheated and shaped similarly to fire, but it does not hold many of the properties found in fire release techniques. Since this technique does not utilize true fire, it cannot light objects on fire by engulfing them, nor can it naturally surpass wind release techniques. Due to this, and much to Nōsei's dissatisfaction, wind doesn't not enhance anything but the concussive force of this technique. Unlike the chakra of a fire release technique the chakra of this technique is not very luminescent, giving off only a ghostly aura in the dark.

Trivia
Despite having an extreme fear of fire Nōsei does not seem troubled by this technique. It is possible that this is the result of the luminescence and coloration, but for now the true reasoning has yet to be uncovered.