Okay, here's Leliana
Backstory's not as fleshed out as I'd like, but I've had a busy week I'm afraid.
The basic idea is that her murderer is her familiar, the cacodaemon who is using her to harvest souls for the greater daemon he serves. When she stops being useful, he'll stop feeding off her (which is causing her to lose memories) and just consume her.
...well, that's one idea, anyway. I'm open to others, or a big mystery for her to solve.