Ryuusan Mist (a Touhou LW original) refers to a mist made from droplets of sulfuric acid. This is the temperament of Medicine Melancholy from the world that's wildly in bloom. Medicine is imbued with Wood Phase since she primarily uses poison derived from plants, and Sun Essence since the Sun lovingly shines down on plants, helping them grow. The strong and kind Wood Phase resists Water Phase, because water nourishes wood, but it is weak to Metal Phase, because metal carves wood. The alluring and arrogant Sun Essence resists the diverse and uncooperative Star Essence, but it is weak to the cooperative and indecisive Moon Essence. She is also chronically poisoned. (Strong against Wood Phase.)

The ability of Medicine Melancholy from the world that's wildly in bloom (a Touhou LW original). This ability doesn't seem any different from the Medicine of our world's ability. The 9th Prolonged Incident. Under normal circumstances, this incident occurs once every sixty years, which makes it a regular feature in Gensokyo. It could almost be labeled a natural phenomenon, and the Sages of Gensokyo and the Yama in Hell surely know of it. Given its nature, prolonging this incident should be extremely difficult. Perhaps, then, the 9th Prolonged Incident is ultimately destined to end on its own, just as the original, unprolonged version did. This would mean whoever is behind its prolonging may be doing so for impulsive, emotional, and selfish reasons. Or perhaps prolonging the incident wasn't their goal at all, and it simply occurred as a result of their actions. Very little is known about Medicine Melancholy other than that she was once an ordinary doll, abandoned on Nameless Hill, and after being exposed to the poisonous lilies of the valley for many years, she awoke as a youkai. Not long has passed since then, and both her actions and way of thinking remain childish. She naively wishes for a future where dolls are freed from human control... but that's about the extent of what can be said for certain. In this world, it's possible Medicine was complicit in prolonging the incident. If she continues to exert such powerful control over poison temperament, her "toxic nerves" will expand further and further, eventually covering Gensokyo and the entire world (to cover the ENTIRE world would take centuries, but still...). Before long, the sixty-year cycle that arises from the temperament flux of the Three Essences, the four seasons, and the Five Phases will be paralyzed by her poison and grind to a halt. As a result, the new sixty-year cycle would fail to begin. The following account is taken from a false text, but it is believed that much of it applies to the Medicine Melancholy of this world. Around sixty years ago (in the mid-20th century in the outside world, based on the original incident's timeline), Medicine belonged to a young girl, the kind of child perfectly suited to care for a doll. The girl cherished Medicine and saw her as her best friend. Then, a great war broke out, and the girl's parents discarded her beloved doll. The doll, you see, originated in a foreign land―a land the girl's country was now at odds with―and her parents wanted to conceal the fact they had bought it.