I looked at your team and see that you have two 6-star mages, which is very good. Your priest would be more helpful if it could shield two at once, but the resurrection set may be good enough though.
Do you have arcane blast on both mages? I hope so! (You have to actually go to the skill screen and pick it, which I forgot to do once.)
It looks like your Rose is the stronger one. Is she able to kill all 6 monsters in one shot of arcane blast? If so, can Joenne kill them all in one shot too?
If Rose can, but Joenne can’t, then Joenne may just need another “Mystery” item to get the set bonus and do more damage. So, you might be closer than you think.
When both can kill everything in one shot, then you might be able to finish the stage by trying over and over until you get lucky. The trick is to get Rose to kill all 6 monsters in one round and Joenne to kill another 6 monsters in another round. Makes it SO much easier, but for this to happen you typically have to replay a stage many, many times, until you get lucky. Killing all 6 will not happen on the first set of monsters. Don’t even try. It will be the 2nd set and the 3rd set If things go well.
If you aren’t able to do it, then escape. It doesn’t cost you anything to escape, so you can try over and over for free, until you are able to do it. I’ve spent a good hour fighting the same battle over and over if there was any hope at all. Sometimes it really pays off to keep trying!
So much for random chit chat! This is definitely game advice. And maybe advice you already know. Hahaha! 
P.S. Also tends to require luck with Fireball. On the first set of monsters, you need fireballs to kill more than one monster, or you’ll be stuck there too long. Being stuck there too long means arcane blast will trigger on the first set of monsters, and that will throw everything off.