Let me explain how those tough boss fights work with their special resistance ability (which, by the way, is why some early attempts might have felt impossible). When you're facing major enemies, they've got this clever defense system that gives them a +10 bonus to saving throws against your control spells - and they can use this trick three times during the fight. This actually makes a lot of sense from a design perspective, because it prevents you from just stunning them right away and winning too easily.

Here's something interesting - you can actually work around this by being a bit strategic. Since they only get three uses, you might want to bait them with less important spells first (things like blind or command work great for this), and then hit them with your heavy-hitting control spells once they're vulnerable. It's worth noting that this bonus specifically helps against incapacitating effects, which is why some players mistakenly think their major spells aren't working at all.

You'll notice the fight typically has distinct phases, where the boss starts out really resistant but becomes more vulnerable after using up their defenses. This creates these perfect windows of opportunity where you can finally land those big control spells (and believe me, there's nothing more satisfying than finally landing that crucial hold person when they're out of resistance uses). Remember that damage-dealing spells bypass this system entirely, so mixing up your approach usually works best.

Try to keep track of how many times they've used their resistance - once you see that third use, you know it's time to unleash your most powerful control effects. And just between us, combining this knowledge with environmental hazards can make these fights considerably more manageable.