I would try a combo with coldheart, Royal Guard, rhazin, apo and mm. Make sure coldheart has enough acc for turn meter decrease and Appo has enough speed 170+ so he can keep the tank alive.
Finished missions on my alt with this comp so I can get behind this. Hit the right stats and you'll be set.
So go in with Rhazin, Mortu, Apo, CH, & RG? That works even though 3 of them are wrong affinity? Also, what gear should they be in? Any suggestions?
MM is Miscreated Monster.
You only really need to finish this for the missions right? If you go unlucky with weak hits from Royal Guard, just restart the run. You'd want to be farming stage 16 and up anyway. So once you get to stage 17, that comp will be consistent enough where you can farm accessories and silver to get yourself ready for the stage 20 push.