My Crusnik love Able X O.C

Elizabeth Ignus, an original member of the A.X, she was originally kept in a place that illness ran rampant before the wars, before the vampires even came to earth, she was 'killed' more like forced into a portal that had taken her to the realm of the Ashen One, He trains her to be a very strong and wise warrior, after returning she lives with her sister, who by now is much older, and very sickly, she finds out that because of her time in the Maw, the place a very power full illness is she has blood that can cure any thirst of the Methuslas, an order of knights is founded that quickly become known through the Methusalas world as the 'bloody Alices' a specialized squad that take orders directly from the Empress or Emperor.
Able Nightroad, A Crusnik that also works for the A.X, his past shrouded in mystery to almost all of them, he's known by another name to the Bloody Alices, The Black winged King, or Just The Darkened King, How does mates play into this, and How does Elizabeth know so much about The Crusniks, yet almost nothing about humans?
Disclaimer: I don't own trinity blood or the media used in this book.