No, Moon Breathing is not inherently a Blood Demon Art, but Kokushibo did integrate it with his Blood Demon Art.
Kokushibo, the Upper Rank One demon, originally developed Moon Breathing as a human swordsman emulating his brother, Yoriichi Tsugikuni's Sun Breathing. After becoming a demon, he enhanced and adapted Moon Breathing. The reference text states that he spent years honing Moon Breathing both as a human and later, "in tandem with his Blood Demon Art," ultimately perfecting a fusion of the two. Therefore, his specific version of Moon Breathing is intertwined with his Blood Demon Art, but Moon Breathing, in its original form, is not a Blood Demon Art.
In essence:
- Original Moon Breathing: A sword technique developed by Kokushibo as a human.
- Kokushibo's Moon Breathing (as a demon): A fusion of the original technique and his Blood Demon Art.
Therefore, while Moon Breathing started as a sword style, Kokushibo's demonic version incorporates his Blood Demon Art.
