Re: Acid Storm, What counters it?
 

Yes, Acid Rain damages armor but do not destroy it. Acid Storm however...
But as there seems to be a lot of confusion on this I'm just gonna clear things out by quoting the manual:

Acid Storm (p. 260): [Second row] "All armors are destroyed, like Armor of Achilles."

Armor of Achilles (p. 243) [First row] "Destroys the target's armor, reducing its Protection."

Rust Mist (p. 244) "All armor in the area of effect becomes rusty. When struck (and after damage is calculated) the armor has a 50% chance of becoming "broken" [Acid Storm gives instants broken armor] and conferring no Protection bonus. Broken armor has the same effect as Armor of Achilles."

To summarize: there is a difference between "broken" and "rusty" armor. Acid Storm gives "broken", Armor of Achilles gives "broken", Rust Mist gives "rusty", Acid Rain gives "rusty".

Re: Acid Storm, What counters it?
 

good creatures to use would be ones with good regeneration maybe trolls, but probably something like tarasque would be better,or those kind of statues in enchantment, spells like acid storm and fire storm don't do a huge amount of damage to single units and don't always hit, so something with regeneration and decent hp is likely to survive.

um a good strategy to try would be using say EA C'tis' sacred serpent dancers, get a water, nature and air blessing, so they have even better Def, regenerate and have some defence against incoming missiles, remember they already have like no armour so you just have to outlast them.