The Underground Guardians is a side series based off the main series, the Promiscus Guardians and features Simon, Chief of the Guardians. Presently, there is only one book finished in this series: When Darkness Breaks.

If you want to step into the grey area between good and evil, then this book series will show you that only a supernatural creature's heart can ascertain if they're good or bad. 

Ebony is a demon and Simon is an angel, but both find love and the shades of grey that lie between.