Biome Bundle 6.1
Forge 2768
The Twilight Forest 3.8.689

Twilight Lich's are spawning in the caves of the Swampland Spooky Biome. It does not appear to be a biome ID conflict, as it happened both before and after I changed biome IDs (this was to fix an unrelated issue with galcticraft biomes). Obviously these boss mobs should not be spawning in non-designated areas in the wrong dimension. I'm unsure what to blame, but seeing as it happens only in this biome, I have a feeling this mod is somehow involved.

Not to be a nag, but it's been over 2 months with no response from any side about this issue. I also see a lot of other bug reports going unanswered. I like this for world generation, but I am considering dropping it from my pack as an unsupported/dead mod.

Found the issue: https://github.com/Tamaized/Dal-Quor/issues/239