A number of years back my regular D&D friends and I teamed up with a classmate we hadn’t played with before. He had arrogantly said something about kicking our asses with the kingdom he’d developed, so naturally, challenge accepted. One of our friends agreed to be the impartial DM.
I was playing a super-powerful anti-paladin at the time, and, in a reconnaissance foray, he was promptly killed when we discovered the entire kingdom was protected by an anti-magic shield.
My buddies strategized and attacked using a high-level druid and his acolytes. First the druids summoned a hurricane, which made short work of the kingdom’s anti-magic shield using tornados and non-magical lightning strikes.
After weakening his kingdom’s defenses, the DM revealed to us the kingdom’s power source for the shield was tapping the soul energy of prisoners – and this was long before the Matrix movies.
The moral of the story, I suppose, is don’t challenge a druid without a clear understanding of their capabilities.