For Cb,Attack Down,Poison,Hp Burn,Defense down or weaken and a good healer will help.Speed needs to be around 160 I think for hard CB but I could be wrong.Fire Knight use heroes with multi hit A1 ability...will break shield faster.Arena speed is everything it seems like until Gold?Nukers with AOE Warmaiden if u have her for Defense Down AOE should help a bit.And get them as fast as possible.Warmaiden should go first or a champ that has turneter boost then Warmaiden.And a speed aura for leader.Hope this helps a bit

Ohh.And spider all AOE  Nukers with a good healer to heal your champs.

I believe u got Miscreated Monster.A beast in Arena.Should be very useful in dungeons as well