Holy Avenger, the one causing all the fuss at the moment. Now, having tried this about 10 times, in its duration I managed to get out 3 Crusader Strikes and 3 Judgements. This amounts to 6 so will amount to 18 Holy Power generated per 2 minutes, which is 12 more than otherwise.

Due to Grand Crusader, 20% of those Crusader Strikes will proc Grand Crusader. (3*0.2) = 0.6 Avengers Shield procs per Holy Avenger. Due to each one of these generating 3 holy power rather than 1, it becomes (0.6*3) = 1.8 Holy Power through Avengers Shield per Holy Avenger. Add this 1.8 onto the original 18 and you come up with 19.8 Holy Power per 2 minutes. Multiply this by 1.5 to get the number per 3minutes, which is 29.7 Holy Power generated per 3 minutes via Holy Avenger.

However that is not the end of the story - Sanctified Wrath gives a 5 NET gain, and Divine Purpose gives a 15 NET gain. 29.7 is the TOTAL generated, so to find the NET gain you must subtract what you would have generated otherwise. 3 Crusader Strikes and 3 Judgements makes 6 Holy Power, and then you must add on the 0.6 from Avengers Shield in the same time period, making 6.6. 29.7 - 6.6 = 23.1 NET gain of Holy Power.

Not only is Holy Avenger controllable rather than RNG, but it also grants the biggest net gain of holy power which is the important bit.