This is useless in PVP, right?
Yep, very useless. Might work on loose hunter pets, but god knows why you'd use it on them.
Are you sure it works like the priest's fade ability? From what I've read it works more like the rogue's feint ability. The threat reduction from fade is only for a short amount of time (about 10 secs) while feint lowers the threat for the entire fight.