I did up to wave 29 in grace set as classic barb. I would reckon going for more AP for battle 30, and possibly 29. Both doable without, but may depend on morale procs etc.
With battle 30, if you let them cast, it will be much harder than if you stop them beforehand.
You use it on the first turn and then a new wave of crocodiles comes running at you ) Or you can wait for an another wave, so will be able to hit more targets at once))
