A remix of Okina Matara's two boss themes in Touhou HSiFS: her stage 6 boss theme "The Concealed Four Seasons" and her extra stage boss theme "Secret God Matara ~ Hidden Star in All Seasons".
The style is mostly orchestral, with electronic and rock elements thrown in. I learned many new music techniques for this arrangement.
Art by shan; link: http://danbooru.donmai.us/posts/2818791