I was under the impression that communion master spells affected all of the slaves. Has this been changed, or was I mistaken?
Astral 9 would work, but Earth 9 is only useful on units that already have high protection, like Templars and Wardens, IMO. However, communicants are not sacred. Mass Protection should save some units...
Killing the enemy before he casts - with fliers, spells, or longbows of accuracy - is always best, though
