Boil Release: Skilled Mist Technique

Mei creates a cloud of mist which she releases from her mouth. This mist has corrosive properties, capable of even melting the bones of the Susanoo. The technique has an inherent disadvantage in that its effects are indiscriminate, limiting its usage to areas that do not presently contain allies until the attack is completed. In the event that the mist escapes the containment area, thus putting others in danger, the user can sufficiently manipulate its acidic qualities to safer levels by adjusting the pH levels of the mist.

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.