Acidic Rain

You conjure a floating green could of acidic gasses above an area within sight and range, the cloud covers a 60feet cube. each creature inside the area when it is conjured or that starts t's turn inside the rain makes a Constitution saving throw, on a failed save, they take 4D10 acid damage, half as much on a succesful save. additionally, any non-magical armor and weapons become damaged and take a -1 penalty to their damage or AC on a failed save. once a weapon or armor has a -3 modifier, it is destroyed and rendered useless.

Higher level casting. for each level above 7th, the damage increases by 1D10 per spell level.