http://dom3.servegame.com/wiki/Eater_of_Dreams
Eater of Dreams is a doom horror, one of a couple of super-horrors that sometimes attack if you have a lot of horror marks. Im not sure what other factors are involved, but as Loren said, casting non-blood spells under astral corruption does risk provoking a horror attack, and the wiki says that the chance is proportional to the amount of gems used. Ashciac record uses a lot of gems, so that is probably what happened.
The only other way to see doom horrors is to wish for them specifically, or for a doom horror (to get a random one). They have a 50% chance of attacking you when you wish for them, though, and they can only be controlled for a few turns even if they don't, so you don't see too many people wishing for them.
Re: Eater of Dreams
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