This is Patchouli Knowledge's theme from the fanmade Touhou game published by danmaq, Touhou Mutsuigeki ~ Concealed the Conclusion
Original: ラクトガール ～ 少女密室 ／ Locked Girl ~ The Girl's Secret Room
(Patchouli Knowledge's theme, from 東方紅魔郷 ～ the Embodiment of Scarlet Devil)
You think I'm scared of you, Patchouli? I mean, you were even weaker than Remilia in the first game, and I just kicked her... *pulls out spell card* ...ass...
Uh.
Oh jeez.
RUN MARISA RUN.