Mu-un (a Touhou LW original) refers to a clear blue sky devoid of any clouds. Junko's temperament has been purified by her ability, so she does not resist, nor is she weak to any Phases or Essences.

This is the ability of Junko, a being without a name. This mysterious ability does not simply act as a filter that removes impurities. According to an unknown source, it "creates gods." An example of this ability in action was seen when Clownpiece and the other Hell fairies received a boost in power. It is quite astounding that this ability could increase the strength (lunacy?) of the fairies to such an extent that they become beings of pure lifeforce. Fairies are usually seen as embodiments of nature, but this purification transforms them into a state incredibly close to unrestrained lifeforce. This lifeforce, also referred to as impurity by the Lunarians, is what threatened the Lunar Capital. This purification is thought to unlock the true nature and primeval power of everything that is affected by it. Conversely, a name is what contains this wild power. This is why Junko is a nameless being. Gods are a perfect example of this, as their original power becomes limited when they are given a detailed name. In some cases, their power can even change when their name is changed. This concept is connected to kotodama (the belief that souls dwell in language), incantations that make use of words, and the fact that human culture is predominantly built and tied together with language. Within the limits of human understanding, there are always concepts that have not been or cannot be put into words. These are sometimes called mysteries or occult phenomena and do not only exist in the far reaches of space, but also within the human subconscious.