Too powerful? What am I missing... (please help)

[NilesB]

Yup.

I forgot about the Protection From X spells. Starting around level 5, PCs and NPCs tend to use Protection From and Magic Circle of Protection a lot in our games. One just cannot beat the protection versus summoned creatures, let alone the other advantages of those spells. And the duration of the MCP version doesn't suck either.

Protection from/Magic circle against foo do not protect against summoned creatures with an alignment opposed to foo. Arcane Casters can just summon a creature their enemies spells don't defend them against.