Boil Release: Skilled Mist Technique

The user creates a cloud of mist which they release from their mouth. This mist is highly acidic in nature, capable of melting bodies, and even chakra-based defences and barriers, nullifying them. Even Sasuke Uchiha's Susanoo was affected, despite being considered an "absolute defence". The technique has an inherent disadvantage in that its effects are indiscriminate, limiting its usage to areas that do not contain allies. In the event that the mist escapes the containment area, the user can adjust the pH level of the mist to safer levels.

Though the mist is corrosive to all around it, the user seems to be immune to it, as Mei used it in an enclosed area without endangering herself.