Aquaveil - this is targetable defensive cooldown
note you can combo this already existing abilities. it may not seem strong on paper but actually it pretty awesome actually.
Aquaveil + divine benison - this is good mix
Aquaveil + Asylum + regen + medica II
Aquaveil + Temperance + Asylum + regen + medica II
over all this is total 25% damage reduction. 20% increased healing with full regen effects active. with in this given time limit during big pulls you can use holy 2 without seeing your tank drop below 50 mid cast. in raiding it has different effect
Aquaveil + Temperance on tank on team during a big damage or vs tank buster. help your tank out
Aquaveil + Divine Bansion + lilybell