Here we go for the playing as Lux song, featuring the theme of 'Marisa Kirisame'. Lux may be inspired from her (at least the witch-skin).
Marisa Kirisame belongs to the touhou universe and is a powerful witch with black cloak/skirt, blond hair and a hat similar to lux's blue version. Marisa herself is good and bad character at the same time. She switches depending on the situation (+people around her). Compared to Lux she is younger (Teenager) while Lux should be around her 30s and is so far more developed as a woman.
Master spark is one of the youtubers favorite and some sort like Marisas "Ultimate" (=spell card). The song adapts to many music styles. This music here is the rock version by "Ezel Ash".