[Immaculate]

Growth three with pythium prevents loss of most of your theurgs and arch theurgs. Those that did get diseased got a shroud of the saint ('cause of the regeneration on the bless). (I don't feel growth three is worth it for this reason alone however- i would rather just hand out regen equipment or send them into battle against barbs or whatever with a regen bless every few turns)

I can confirm what Corinthian said about bakemono sorcerers with their death magic (even when they have fire 2 or three i don't see them dying too much even in a death 3 domain)