As for the console, there are actually no errors there: it points to some minor flaw in the model of the mindless one from Hannik, as well as to the idle animation sound of the faceless one from Zobrah, which, as far as I know, actually works. This does not affect the gameplay in any way.
Reveran simply attacks the player in a standard way. The battlefield is generated as usual, i.e., randomly.
Yes, the final battle turned out to be easy. I considered ideas for radically changing it, but in the end, I decided to leave it as it is, only slightly changing the number of summons and the order of spells.