I think you are going to struggle against high-toughness and/or high armor units. And (granted, in my opinon) three dispel scrolls on
10 levels of casters! is just plain overkill. Anything that makes it through your
DD should go away handily in
your magic phase when you cast PoD four times, and start dispelling his lasting effects. One scroll for emergencies should be plenty.
If you really want to mess with his magic, give a Master the Ring of Hotek and a Dark Pegasus and go mage hunting with him

and use your overwhelming magical offense to blow up the rest of his army that's
not within 12" of the Master.