cover art for "Now, Until The Moment You Die" by Jienyo
Listen to it here:

https://soundcloud.com/jienyo/now-until-the-moment-you-die
https://www.youtube.com/watch?v=8F_VOgdIuLM

the song is a remix of the original track, いざ、倒れ逝くその時まで ~ Now, Until The Moment You Die (Sariel's Theme) From Touhou Reiiden ~ Highly Responsive to Prayers (Touhou 1), by original composer, ZUN