Pierce the veil offers a 20% boost to my damage, which seems interesting. But I don't know when it is counted. If this is on my base damage, it is pointless because I get 1200% from intelligence. If it is after the intelligence boost however, it gives a much larger boost.
My WD's damage stat goes up by exactly 20% when I spec Pierce the Veil. It's a +20% multiplier that's applied separately from the Intelligence bonus. It doesn't matter when 20% is applied, since multiplication is commutative.