The rules state to draw non-Epic Threat cards from the appropriate Other World deck when you're in another world. Technically that would seem to dictate that you also draw from an Other World deck when drawing for a Chest Portal mutation or to see what Sinister Experiment the Flesh Drones have, but that seems wrong to me. What do you guys think?
We always drew from the normal Threat deck for these, but with this game, you could draw from whichever Threat deck you want. Thematically speaking, something coming out of a portal could come from anywhere (even a different Other World).
Drawing from the regular Threat deck was a habit we started early on, before extra enemy packs. At that point, there were so few Other World Threat cards that we often couldn't get through a mission without reshuffling that deck, and that was without using the OW Threat deck for Chest Portals. We still draw from the normal Threat deck as a force of habit, and to keep a bit more variety in the enemies encountered.