Ok I am almost 100% sure this will not work and is probably retarded to even think about, but that has never stopped me before.
If you rocked a mage with:
1) The 30% Mana Regen talent while casting.
2) No bonus Int gear.
3) A very Low Mana pool.
4) Deep arcane spec.
5) High high Spirit.
Is there ever a time where you could make it such that your mana regen would be so large that Arcane Barrage would essentially be free?
I mean if you had 100 Mana (over-exaggeration)and you cast Arcane Barrage, it would cost 18 Mana. If your spirit was high enough that you regained 50 Mana every 5, could you theoretically never run OOM?
I realize that you will have a substantial Mana pool from base Int anyway, hence why this is probably impossible. I was just wondering if you could come close to this build?