@Kami_Nana @Geohie Right. So I went back to chapters 5 and 12 to investigate better. At CH5 the Priestess shows signals of relief and worry over the Hero still being alive (this can be considered either love or friendship, it's not clear) and decides to investigate. At CH12 she says: "The demons must have seduced my dearest Justy away" and "Release my dearest Justy from your hold, otherwise I'll purify every last one of you" with a serious face. Hmm, it's a weird choice of words for just a mere friend so this can be implied (baited) as feelings of love, but her real motives to wanting Justy back still aren't clear, just implied. The rest is as you guys know.
To me it's clear now that the author just baited people with his choice of exposition and portrayal over her character. After she becomes a member of their party, we don't see any revelant interaction between her and Justy, not even a good talk so we can finally understand her real motives for wanting to find him, so the bait is even more evident. With that said, I still consider her character as a yuri-bait pandering/cockblock character and this is even more apparent by the newest chapter. Yes, I understand that this is a fun romcom not meant to be taken seriously, I just wanted to share this with you guys. Cheers!