Yosharian
Arcane
The problem with low saves is that saves are necessarily binary mechanics. Improving a pitiful Will save to a moderate Will save doesn't really yield good results in most situations. In PnP Iron Will grants access to Improved Iron Will which is an excellent feat because it grants you one reroll a day. But even then, it's still two feats to gain a chance to make a really important save. In Kingmaker, Improved Iron Will doesn't even do that, it's just another +2, so it's barely worth it. Added to that is that a lot of Kingmaker's content has inflated DCs compared to PnP, even on Core rules. Get it later on if you truly have nothing else to get, but don't bother making it a priority, that's my advice.Yeah good luck with that. Use your allies to protect you with spells, or expect to get mind-controlled.
Those are not mutually exclusive. But I mean, lets say you get a few Will save points from levels as a figher (up to +6 at high levels), +2 from Wisdom, +2 from feat(s), some wisdom equipment maybe (i found a hat with +2 wisdom early on), so that's up to +11 will save. Then, you can have almost any caster cast protection from evil or something, and you are up to +13. That's not peanuts, unless the DC against those spells is just insanely high.
Well, you can meet certain enemies reaching DC 22 at level 5... And trouble is some of them really spam those tests.
Protection from Evil doesn't stack with Resistance items I think. But you'll have those too.