ALL avatars? how? Sacrament of Blood is only for one model and only that model gets additional round bonus. You can cast it on avatar / cauldron to "move" it to round 3 so it would be animated AND have hit of 1s re-roll but that is still only one model.
I don't see where it awakes all of your avatars (unless you have only one in the army, then 1 = all )?
@Edit - I wrote for model because I meant avatar or cauldron, normally it may also be unit