Originally Posted by
Nightfall
Well, there's mitigation from lv30 talents and Greater Invisibility, cheat death mechanic of Cauterize, healing with glyphed Evocation and Cold Snap. But mostly you'll want to prevent damage with Blink, novas, Ice Block, Deep Freeze, Blazing Speed and defensive Alter Time.
E.g. properly used Temporal Shield and Alter Time provide you with up to 3 life bars. But if used incorrectly, you die a horrible death (Alter Time at low health, get healed to full, Alter Time back to low health, dead).
The main difference between Mage and Shadow Priest is that you don't tank. There's Blink every 15 sec to remove stuns and roots, there are multiple slows and novas to kite, Blazing Speed to ignore snares, Greater Invisibility is your mini Dispersion and you can also clear all dots and CCs with Ice Block (except Cyclone).