Secret sin

Emile was a demon.
She was born an angel but when the Nuns took her from her parents when she was born to a catholic orphanage she fell and eventually killed everyone in the orphanage after years of them tormenting her.
After that, she killed over 9000 people before the World ended.
That is how she wound up in outpost three and how she met Michael her mate and dark lord and saviour.

Read more to find out how they meet.