Tower of the Fourth Sphere reads "At this location: When you encounter a non-villain monster that has the Demon trait, banish it."
Am I correct in taking this to mean that it is impossible to defeat an Arboreal Blight encountered in the Tower, and that the only way to defeat a Demonic Hordes is to win the ~1/3 chance of not having the exploring character encounter any demons?Edit: Yes, I know there are no barriers normally found in that location.
Written as it is, you seem to be correct. However, since there normally aren't any Barriers at the TotFS, IF there were it's power would probably be worded something like "When you encounter a BANE that has the Demon trait..." (I believe both of those barriers had the Demon trait).
If you're asking about using it in some homebrew scenario, I'd treat it either that way (banishing the spreader on sight), or - which seems a bit more balanced- I'd just treat any Fiendish Trees/Servitor demons encountered at the TotFS as auto-defeated, without skipping the rest of the encounters.
Last I checked, Fiendish Tree and the demons summoned by Demonic Horde both are monsters, so the location effect indeed works as-worded. You would banish the summoned henchmen and they are neither defeated nor undefeated. This does indeed have repercussions on the barrier that summoned them as noted in your original post (Arboreal Blight will always give you a shot at getting Ulkreth or is jus impossible to beat if in the tower itself, and Demonic Horde requires you to get lucky with random selections in order to be beatable). My recommendation would be to clear out and close the tower quickly after encountering such a barrier, or moving elsewhere so that your 2nd shot at it isn't as horrible.
