Originally Posted by
Alkimi
It's a free 10% damage reduction for 20s (which nearly always procs) with no MP cost and no GCD usage. There's really zero reason not to use it or have it in the first place. When Twintania is hitting your tank for anything up to 6k damage (with shield oath), you need all the damage mitigation you can get. Be glad you have it already before you do any difficult content.
WHM isn't the only job that should have it either. If BLMs are serious about doing Turn 5 they should that and Virus both set as cross class abilities aswell.