The Half Lilin — a series by Shin Eris

This is the story of Patrick Willows, an average guy who had an average job and an average life. He was not however, meant to be average forever. Born of a three time antichrist killer mother, descended from a tribe of bloodthirsty pagans, watched over by angels of November and the great Lilith as his Matriarch; you bet he's got a higher purpose. He's destined to fight evil gods, nasty demons and and power-hungry angels. There's just one little hiccup, he has to do all that as a girl. Sucks, I know.