[Pickles]

They cause fatigue IIRC & the spell "Relief" will remove lots of fatigue - it is N3 and Enchantment 6 or 7.
Reinvigoration items might help on your leaders along with life draining effects as these restore HP & reduce fatigue. I am not sure if they do it fast enough though. The effect is MR negates & the spell Antimagic (enchantment 4 S3) boosts MR plus several items do so too.

O fatigue units (most undead & constructs) are immune to spells that cause fatigue & I think this applies to other effects.

The fairy queen is quite high level - attacking soonest would mean she is not yet around.

Pickles