I find int absolutely useless, some may not agree but most do. PIE raises the DoT damage, modifies the drain/siphon mp/siphin tp spells(IE raise the amount you recieve), and is supposed to modify magic accuracy.

MND raises your over all MP pool. It also raises mag resistance as well as it modifies hoe much you can heal for.

I can verify that piety does alot for the DoTs and siphons as THM. charts have been made, I recommend doing a blog search, toms of good information.

What worked for me, was adding evenly to vit/mnd/pie, i think with gear I hit about 115-125ish in all 3.