Fade + 4p pvp set = a 4 sec freedom and a full slow clear every 15 seconds + 10% run speed = BEST mobility of any caster, plus we can cast nearly all of our spells on the move, AND proc shadow apps constantly on the move.
We can do great sustained dot damage OR burst with MS/MB when we're being cleansed.
The best execute in the game.
15% damage reduction and a 90% reduction with just over a 1 min cd.
Priest utility - Hymns, bubbles, mass dispell, offensive dispells, *LIFE GRIP* (wins matches), unique buffs, fear ward, PoM/renew/heals.
Silence, disarm, and fear. (NO other caster has all 3)
TL;DR - if you can't completely *roflpwn* EVERYTHING THAT BREATHES in pvp then you need to L2P.