This is definitely beyond me. My water team is 45K, not exactly perfectly optimised. I can clear stages 1-3 but have nothing left for 4. Okay, I shouldn't have tried with Arthur! Maybe when my primary element comes up I might have a chance.

I am hoping someone will post a viable strategy here, careful optimisation is likely my only hope as I've not got much room to just upgrade in strength. I don't even know how tough Crom is yet. Do we get Crom all week?