Elemental deck I used to rank from 13-2. Great against paladins, sucks against druids. The general idea is to stall with heals and taunts until the aggro opponent concedes, or until Hagatha the Witch and Shudderwock give you endless value.
Then, against aggro I like to keep Glacial Shard , Tar Creeper and/or Hot Spring Guardian. It's essential to have some sort of early game. Also, keep Fire Plume Harbinger if you good elementals to follow it up with.
I don't like keeping Lightning Storm if I don't have any early game, because the overload prevents you from developing after a Call to Arms. You can keep it against mage when you have the Coin, because you don't want storm to get Counterspell.