I tested this devotions with different setups - mostly %dmg reduction lacking classes, such as Pyro, Deceiver, Warlock. And come to conclusion that w/o at least 33% CDR the proc is extreamly unreliable.
It work only with melee AA, so half of nemesis nukes don`t triger it, the chance of activation is only 20% so, its not even up on CD and the CD make it useless when you need it the most.
I suggest to increase the chance of activation to 33% when hit, remove melee requirement and shorten the CD down to 1 seconds.
To compensate, reduce %WD to 20% at 15/15 .