Kruin and Inquisitors, questions Options

[Kerkes]

well, I must say I'm a bit surprised nobody asks help about this one.. (in my latest run, it was the hardest battle for sure. 17 reloads! AAAAAArrrrggh!)
The thing I wanted to ask is this:
Is Kruin immune to "dispel magic" cast from an Inquisitor?
I once played the game with a custom Inq in party (was lvl 18 by the time I met Kruin, I did some of WK, Umar Witch etc.before going back to Alkathla from Underdark). As soon as his buffs kick in, Inq fires his dispel. I get a message : spell ineffective?!
Now, I quit inquisitors for good, and took a blade instead, which, I must say, are 10 times more useful than an Inquisitor will ever be (if you want a powerful dispeller, that is) regardless of his Avenger sword.
Same battle, blade is lvl 23.
Took 4 reloads, and it worked ("remove magic" was succesful.)
What's up with that?

[Kerkes]

@ Sikret

I know about nerfing of Inquisitors very well, but still fail to see how come he was unable to dispel him.. (what good is he if he can't dispel until lvl 20+ !? I hardly even need it after my sorcs get Time Stop and Alcatry...) I reloaded quite a few times, never worked.
In my latest run, took 4 reloads with a 23lvl blade, on 4th attempt he was succesful.
Doesn't make sense to me.
I know about his globes etc.which won't come down with a succesful dispel, but he also starts with a fireshield:blue I believe, which does if it's succesful. Inquisitor never removed it, blade did.