You don't see it much cause its a T6 master spell. The few useful T6 spells everyone has seem to be rare since raiding T6 just isn't all the happening rave. I don't know precisly but, killing ^^^ from TT, or raiding courts or PPR are prolly some good places to start finding some. I've seen my T6's drop from Courts, some ^^ 59 heroic in TT and PPR.