[Bowlingballhead]

As Void Monsters are among my favorite elements in the game, I will fill you in on them.

Priests summon much better than mages. They both seem to summon more stuff, and they are vastly less likely to get feebleminded. By the time one of them GETS feebleminded, you may well have the chalice or gift of health, and be able to heal him. Thus, the sky is the limit for their summoning ability, although eventually it 'maxes out' and all you get are greater othernesses. Which should not be knocked.

Cthugul the Stargazer apparently has a slightly smaller chance of getting feebleminded than a regular priest. Whether you want to devote him to summoning is up to you.

Two strategies to deal with the occasional (well, frequent) monster attacks. Give your priest a squad of tough units set to 'guard commander' (and give him a ring of warning, too, so you can have 10 bodyguards!). Or you can have him set to cast that recall spell first turn of combat. I haven't tried it, but I'm told it will get him away scot free, even from horrors (which attack fantastically rarely, but do attack). I think there's a ritual spell he has to cast outside of combat to 'prime' the recall spell, though.