The start of Everything

Ember Black(my Demona oc with a last name) worked for a business man named Matt Miller. He seduces her and she ends up marrying him. At her bachelorette party, she ends up getting turned into a vampire as another woman's plot to get Matt to be hers. She didn't find out until her wedding night when Matt asked her how her bachelorette party was. He puts two and two together, she was quite thirsty at reception, and test it. After Ember ends up tasting his blood, they confess that they aren't who they seem, Ember being half Demon and half Asgardian, Matt actually being a Speedster from the future name Eobard Thawne. He convinces her to help his plan for ruining his arch enemy, Barry Allen.