A Player's backstory where Lover is taken by Vampires - How could I tie this in?

Hello fellow DM's - I need some help brainstorming possibilities.

I have a player who loves to create elaborate backstories and it's just *chefs kiss* amazing fodder for my DM dreams. This time around, running CoS, her Paladin is on a quest of vengeance against any and all vampires due to her fellow soldier and lover being (supposedly) taken by vampires. With only their lovers ring left behind, they went on a mad hunt where they were swept up by the mists and deposited in Barovia.

In their first encounter with Strahd, he was successful in charming pretty much everyone and during the conversation it came up that she was looking for her lover. So now Strahd knows and has some leverage over her. Here is my thinking though - he is trapped here but has the power to let people leave so could these vampires be connected to him? Or could it be he uses his network to find out about this lover? Would he bring that lover here? How might I best torture this character now that Strahd has this information?

Any ideas or thoughts?