you posted this 3 times.
mana shield is all of a sudden so important because its new and we've never had it before, we get it on monday after the update.
maxed out mana shield diverts 50% of the damage you take to be subtracted from your MP and not your HP, and since you are pure int you have a shitload of MP to keep you alive for a decent amount of time.
add that to your blocks from the shield and the straight out light nukes and ice nukes you will be shooting and you will be a killing machine.
fire is taken out because the only reason int;s have fire right now is to cast the stronger fire nuke, but with mana shield, frost guard, defense passive, and a possible ice imbue to freeze euro chars, ice seems like a better alternative to fire.
light would be your imbue, and the new light nuke is really strong and rivals the fire nukes.
there ya go.
http://www.youtube.com/watch?v=0J7YEPSfsk4
watch some pure int s/s with mana shield in that vid, its an int tank with insane nukes.