Evangelist Spectre (GGG can you clear up some questions?)

They cast a short-duration bubble that protects all allies within it form daamge that originates outside the bubble, as you noted.

They also have a delayed blast spell that marks an area of ground, then shortly afterwards deals physical spell damage in an AoE at that point. I believe the damage is quite good because the player is given warning and a chance to get out of the way by the ground being marked before it goes off, but I don't work in balance.