Heya!

First of all, holy gods is this mod incredible - I've never quite found a something like this, something that genuinely makes me shudder and leaves a lingering sense of dread. Bravo, truly.

But, on to the matter at hand.

When I first entered Arche, I noticed that none of the Ictya were spawning. Further experimentation and past experiences led me to suspect that DrZhark's CustomMobSpawner - which I use for Mo'Creatures - was the issue. Upon removing it in a clone of my playthrough, the Ictya began spawning normally.

Forgive my ignorance of coding, but I would suspect that this would not be easily fixed, and also that it would have a low priority, seeing as it is a compatibility issue rather than anything related to Beyond The Veil itself. Nonetheless, thank you for your time, and for being such an active and friendly developer.

CustomMobSpawner is incompatible with most other mods by default (excluding a few which have hardcoded support). I'd recommend removing it and using Mo' Creatures standalone (see ACGaming/UniversalTweaks#125)