Spoiler! She’s actually psycho and convinced herself that Blair forced Herdin to marry her and is making him miserable. She justifies her love for Herdin and the terrible rumors she spreads about Blair later on by thinking she’s justified by “freeing” Herdin. In the first life she staged Blair walking in on them and told Herdin of her plan RIGHT before. So he decides to play along to get Blair to stop loving him (cause the curse thing only works with mutual love)

let me guess, in their previous life, that priestess was either helping him investigate the incident and her feelings were unreciprocated, or he was faking a relationship to push her away - in order to protect her, of course! not to mention she is his first and only love! i love cliches when they are fun to read, though. i like this so far