How does this thing work vs spells? A comet of cassandora lands next to my mage priest - i have the divine plaque - do i get 2+ ward save vs the comet? What about other spells like fireball? How about pit of shades or purple sun?? thanks!!
It works against any ranged attack that would allow a ward save. Fireball and Comet, yes. Pit of Shades and Purple Sun, no. Typically, anything that forces a characteristic test and removes models that fail can't be guarded against.