In Touhou: Embodiment of Scarlet Devil, what song plays during Flandre Scarlet's boss fight?

In Touhou: Embodiment of Scarlet Devil, "U.N. Owen Was Her" is the song that plays during Flandre Scarlet's boss fight. This particular piece of music, composed by ZUN, has become iconic within the Touhou series and is often associated with Flandre Scarlet herself. Its intense and fast-paced melody perfectly captures the chaotic and unpredictable nature of Flandre's attacks, creating an exhilarating and memorable boss battle experience.