I love how you can still sympathize with most of bad guys in Carmilla. Mattie (I know Mattie isn't technically considered a bad guy but she's close enough to one during most of season two) simply needed to do what the Dean told her to do if she died but she was unfortunately killed. The Dean was driven mad and bitter over losing her love. Elle was a young girl who was tricked by the Dean into think Carmilla was a horrible monster and then sacrificed. Even though what they did to get what they wanted (Mattie wanted to leave Styria as soon as possible, the Dean wanted her love back, Elle wanted to be alive again) is still horrible you can still understand why they did what they did.