What's your team look like? We might be able to make things easier for you.
Team I used for the stage I mentioned was
[L]Icedragon Plesios/Frost Demon/Undine/Dark Knight/Devil Dragon/[Icedragon Plesios]
My "main" team, if you will, consists of
[L]Hellray Harpie Demon/Pyro Demon/Icedragon Plesios/Taur Demon/Devil Dragon/[whatever partner I happen to use, though I'm partial to Baal right now for most things.]
I've been trying to level up my Echidna so its stats weren't so terrible since Menace is so useful, and I do also have other ripper dragons and two other Mystic Knights or evolutions thereof.(Phoenix Knight and Stone Mystic Knight, to be exact.)
From an earlier post it sounds as though I've potentially got a start to a Dark team thanks to also owning Vampire Lord, though I've some reservations about trying to level that monstrosity up...(almost 17k Exp for 30-31...)
I wanted to roll this GodFest, but I was short on stones while it was active, so I'm waiting for the next one and trying not to spend any til then so I can get a shot at something useful.