Blessing of Yogg-Saron

While Herald of the Depths is active, you now transform into a Faceless Monstrosity, increasing your critical healing and critical strike chance by 20%, but reducing its duration by -5 sec. In addition, while active you are now immune to fear, horrify, and polymorph effects.

While Herald of the Depths is active, your critical strike chance is increased by 20% and you are immune to fear and polymorph effects, but its duration is reduced by -5 sec.