I'm sorry, from chapter one until now Haena only gives me vibes as a supporting character, maybe they would give her a good ending but I don't think it will be with Abel.
It is evident that Yeonli is going to be redeemed and I think she will stay with Abel against all odds.
I think Cain just helped Yeonli with the plan to destroy the queen of he**, the evil demons, and the religious sect.