So I've been playing around with Purifying Fire, and I am getting some really, really random results. As you might figure, it behaves quite differently than what the tooltip would suggest. For one, when it procs, it is doing a lot more damage than what you might expect; it seems to be interacting with different buffs, but I haven't really sorted it out yet. Also, it seems to proc at really random times; some times it will proc right after an encounter, and other times that same encounter won't allow it to proc. The tooltip suggests that the encounters cancel the effect, but I can't figure out the timing. I've tried testing to see if there was some type of internal cooldown to explain why encounter powers seem to randomly proc it or block it, but I can't discern any regular pattern. (For clarification, I understand that it is actually at-wills that proc Purifying Fire, but there doesn't seem to be any rhyme or reason as to what gives it a "go." In other words, I can at-will x5 (proccing Purifying Fire on each hit); use an encounter to cancel/reset the purifying fire effect, and it seems to be totally random as to whether or not it resets. FWIW, it seems to be a real doozy with radiant strike.
Any clarification is greatly appreciated.