Not trying to burst your bubble, but I don't see why you would want to. At best I can see it as a novelty to shoot out a few instant cast ranged spells, but if they are going to be range then they are not going to be taking damage. If your not taking damage, what is the point of plate armor. May as well pick your glass cannon of choice who is going to FAR better suited to do range damage than a paladin burning through a small set of spells with 15-30sec cooldowns.

Also every class can do the same 4 or 5 of this spell will one shot level appropriate mobs. 5x exorcism will be neat on Undead/Demon, Guaranteed 5 crits.