First, we need to find the total mana spent per second (in percent), so we take the cost of a spell and divide it by the cooldown. (I'm assuming you have improved judgements)Originally Posted by Phr057
CS: 8/6 = 1.3333....
DS: 12/10 = 1.2
Judgement: 5/8
CS + DS + Judgement = 3.158333...
So using each ability every time it is off CD will cost us 3.16% of our mana per second. Now we need to find out how much mana we will be getting back from JotW per second, which will be found by dividing the amount of mana gained by the cooldown of judging.
15/8 = 1.875
So each second we will be gaining 1.9% mana per second from JotW alone, which means we only need about an extra 1.1% of regen per second in order to have near infinite mana while maintaining our rotation. JoW will be granting 1% every now and then (I'm not exactly sure about the proc chance and such on it at the moment) and we will also have Replenishment, so our normal rotation should be sustainable. Also, this doesn't factor in Divine Plea which we will have at 71 (25% mana every minute), nor does it take into consideration the set bonus of t7 which is an additional second off of the Judgement cooldown, which boosts the mana per second of JotW to 2.143% (although mana consumption is also raised to 3.248% per second), and I'm also not taking into account Benediction, which will of course lower mana consumption.
Edit: With Benediction, our mana consumption per second drops to 2.8425%