It is possible to play a warrior priest from start to end on nightmare mode without any use of ranger skills and only with Mana Eff. (and ev. Healing) as extra mage skill(s) .
And without any hard trouble killing hard mobs (like Amdusias, Black Ring's, Chieftains, Skeltons, etc ...
But I've to say that Charm & Blind are very handy/powerfull Priest skills !! And the Summons (Ghost, Undead, Demon) too, but here you MUST upgrade them always if you can upgrade them wink
On my current play I only go for the Summon Ghost (and my Creature) ... more temporaly allies I make via the Charm skill smile ...

Never I've had the feeling DKS was that easy playing nightmare mode with a warrior priest !

@Raze :
when I write down the word "pure" build then it's a "pure", so only skills from 1 class wink
I know that's narrow minded to say it this way, but know that I myself don't love "pure" builds. wink
On the other hand: it CAN be a nice challenge to try a "pure" build (with a little few exceptions like for the skill Mana Eff., for example ) smile


On 7th of february 2015 : I start a new adventure in the Divinity world of Original Sin,
it's a Fantastic Freaking Fabulous Funny ... it's my All Time Favorite One !