Clerics have a skill called Prophecy that will block all incoming dmg from 1 attack every minute or so, or they are affected by Soulforged enchant that renders them immune to damage for 2-4 seconds when they hit 25%
Bloodtheft is once a min, Lifedrinker procs on every hit. Unfortunately for GFs tho, weapon enchants do not proc while we are using our Aggravating Strike and Shield Bash, largely rendering every single weapon enchant in the game absolutely useless for some builds.