This is Mima’s theme from Touhou 2: Story of Eastern Wonderland
Mima is one of my favourite characters, she’s one of the truly evil bosses of the entire Touhou series (there are what, 3?) I’ve always prefered Complete Darkness over Reincarnation, but Reincarnation is pretty awesome too.
Mima~ Did you really teach Marisa everything she knows? (Mima must have been a master criminal! You shouldn’t teach youngsters bad habits, Mima...)