DESCRIPTION:
Title: Time Will Tell
Circle: A-One
Album: TOHO EUROBEAT VOL.10 HIGHLY RESPONSIVE TO PRAYERS
Release Date: 8/16/2014
Event: ミックマーケット86 (Comic Market 86)
Arranger: T. Stebbins / Singer: T.Stebbins / Lyricist: T. Stebbins

Original song:
Sariel's Theme ／ いざ、倒れ逝くその時まで
東方靈異伝 ~ The Highly Responsive to Prayers

This is listed as The Positive and Negative on the album, but I'm 99% sure this is Sariel's theme.

Picture artist: Nanatuki13
http://www.pixiv.net/member_illust.php?mode=medium&illust_id=21211521

http://a-one-records.com/