I have a warrior as main tank, he is Paly/Reaver and I have that ability from both lines. It doesn't hit all the mobs, it only hits 10 and is on a 1 minute timer (also not a dot if I remember correctly, maybe we aren't talking the same ability). As I have 2 of them I can potentially hit 20 mobs (unlikely though as there would be overlap between the 2 abilities), that still leaves 10 archers to turn my cleric in to a pincushion.
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