Hyouga (a Touhou LW original) refers to glaciers, great big chunks of ice that form near the poles or at high altitudes and slowly move under their own weight. Cirno's armor kind of acts like a space suit, shutting her off from the surrounding environment to help her conserve magic and coldness. It isn't made out of real-world metal but out of a fictional material that only exists in fantasy. Her armor is also a representation of how ice gains properties similar to noble metals at extremely low temperatures. Cirno's original temperament (Water Phase and Star Essence) has combined with the temperament of armored fairies (Metal Phase). The flexible and patient Water Phase resists Metal Phase, because metal collects water, but it is weak to Earth Phase, because earth directs water. The diverse and uncooperative Star Essence resists the cooperative and indecisive Moon Essence, but it is weak to the charming and arrogant Sun Essence. The cold and silent Metal Phase resists Earth Phase, because earth bears metal, but it is weak to Fire Phase, because fire refines metal. The combination of Water Phase and Metal Phase cancels out any resistance or weakness to Earth Phase.

The ability of Cirno, the armored fairy (a Touhou LW original). Cirno should be capable of manipulating cold, and while the Cirno of this world appears to have retained this ability, the surface-level information regarding it has been lost. In an island nation in a parallel world, around the time when the city-dwelling vampires began to migrate east to find the paradise of legend, the fairies were faced with a dilemma. They racked their (somewhat tiny) brains to try and figure out how to deal with the impending loss of fantasy. The humans had almost completely stopped believing in all things fantastical, including youkai, fairies, and even gods. The fairies used to be found all across Europe, but now they were confined to a remote corner of the island nation in a place they call Fairyland. This Cirno is one of those fairies. The fairies in Fairyland are known as armored fairies because of the armor they wear. This armor appears to be their last means of survival in a world where fantasy is steadily disappearing. Each fairy has their own suit of armor fashioned from their affiliated temperament condensed to form a material as hard as steel. In Cirno's case, her armor is made out of ice temperament. The armor acts as a barrier, completely shutting out the surrounding environment while also maintaining an ideal living environment for fairies within it. The fairies made their armor bigger than their bodies to increase the size of this ideal environment, causing them to look quite intimidating. However, since their armor's size is dependent on the amount of magical power they've managed to store, this Cirno is only about the same height as Reimu. The first fairies were lesser gods of nature, and due to the connection between hair and gods, the fairies of this world have different colored hair. This change has also affected their spiritual and mental temperament. The color of their hair has shifted in hue toward red like so: - Yellow-green to golden blonde. - Orange to red. - Beige blonde to rose gold. - Dark brown to maroon. - Golden blonde to orange. - Teal to green. This color shift appears to have been caused by a past incident when this world was suffused with scarlet magic. However, further investigation is required to know how or why this incident occurred. Following the above examples, you might expect this Cirno's hair to be purple, but it is, in fact, bright red. It's speculated that this is because Cirno's hair was never blue but the color of water (or ice). Since water is transparent, it was dyed fully red. Many things in the natural world have color, even light, but water does not. When you see a blue lake or ocean, what you're actually seeing is the color of the light, not the water.