I own nothing.
Im sorry my dudes and dudettes. I've been trying all day for a f2p solution and couldn't make it work. Been trying with Smite, shove, drawback. Nothing was working. Found a guy on my friend's list that was sharimg L!Azura and that solved all my problems.
That guy up there made it work with a 4* walhart. So, if you lack L!Azura try his/her method.
What you need.
Slot 1 and 4. 2 WoM ranged units with their lowest might weapon equipped. Ignore fortress seal.
Slot 3. One L!Azura with only Grey Waves and WoM equipped.
Slot 8 one brave lance flyer. With fury 3. Lunge. And Galeforce.
All other spaces should be filled by your unequipped level 40 hm batteries.
Any issues leave it in the comments.