Found it odd that "Summon Demon Lord" could not be cast on the temple of baal. Not sure if this is true for other special temples...

Is it intended to be ancient temples only? If so, the description is incomplete.

Well this is annoying, this means that apparently the "Temples" terrain group doesn't actually contain all temples and I'll have to create a custom one.

The Djinn is a very crunchy addition, adding some much needed texture to a class that is otherwise a pretty straight-forward sequence of summoning this or that.

There's currently a little weirdness between the Djinn's different rituals... You can heal until you do something else, for instance. Wealth, Conquest, Vengeance, and Power all seem quite castable. Knowledge seems pretty meh, I mean heck, other classes have this effect repeatable for cheap. Wonder is a rarer and more expensive effect, but is very likely to wiff with some bad item.

Here's an idea: For knowledge, wonder, and health, as weaker wishes, maybe casting this transforms the djinn into a specialized djinn that only has that ritual, and can repeat it for a sacrifice cost ranging from free for health to expensive for wonder.

Glad to hear you're digging the Djinn! Both Knowledge and Wonder were recent additions with Knowledge being a more situational "if you need to track down that last pesky commander" and Wonder as a gamble if nothing else is currently needed. That being said, no reason that can't be made more appealing/on par with the original 4 on the next pass. Knowledge I think could end up being a, "Djinn of Knowledge" that can scry along with another suitable bonus. Wonder I would like to test a bit, on paper it has a very generous % chance to roll a rare quality item, the highest possible for an item creating ritual. If it turns out even that is still rolling a common quality item too often I think it can be buffed with rolling a diced amount of "gift bearers" so it can be more appealing while still being a 1-time cast/gamble.

About the tier 3 ritual that opens a gate to inferno...

It seems like it wants to have a niche as a "nuclear option" that you cast deep in enemy territory to screw them over. But the way the Inferno faction AI work, it's kind of... not. A big part of it is how they aim for population centers--Demonologist's preferred terrain, while avoiding mines and forests. I experimented with it, cast it RIGHT next the Dwarven city, only to have the demons congo-line away back towards my territory.

Given how futzing with the outer planes is... aspirational in the current build, I'm going to pitch a rework that basically "fakes it" to get a ritual that hits the flavor notes while still being castable as a non-meme option.

It does involve tossing the old mechanics entirely. No more demons pathfinding from inferno. Instead, the tile would spawn new demon units, that would "snake" around randomly like independents. They would belong to the "special monsters" faction, making them effectively hostile to everything.

It would also still be a portal to inferno, except without creating a way back on the other side. One-way, if you will. This is fine for demonologist who already has a dubiously useful return spell taking up a spell slot.

Good observation, that definitely throws a wrench into the intent of the ritual and makes it too niche if the demon's behavior is too focused on specific terrains. I think this may have a simpler fix of adding a behavior tag on demons that makes them very aggressive towards any "player" owned units/tiles, but if that doesn't pan out such a rework could be worth testing. A few thoughts on other subjects:

One adjustment I will be making is restricting "lower tier" units from being capable of creating a "hell pit" manually by digging down through Agartha. This will still be possible through "god" units like King of Earth or Earth Made Flesh, but currently this is doable by a 10 emerald cave grub which makes the demonologist's tier 3 ritual feel rather lackluster.

The "infernal teleporting" rituals I think are decent in concept but could use further tweaking. A 2-turn fast travel back to home base with a 1-turn layover in hell (possibly longer if cast at low resources) and if one really wants to they could try to capture some infernal tiles before returning or wait to rendezvous with a powerful summoned demon that was banished in combat. Currently they are learned separately at levels 1 + 2, This would be more useful if learned as a pair both at level 2. 50 Sacrifices per ritual is also quite expensive for a teleportation effect, so a significant discount is likely needed as well.

Broadly speaking, interaction with outer planes will probably not ever be expanded in a huge way. I think they're fine as sort of these dangerous "extra levels" that are hard to access and don't count towards victory. Certain classes can access certain planes more easily, but as a part of another effect that ultimately ties back to Elysium, and not having interaction with an outer plane as a big focus of the class since it takes place in a zone that other players will not be able to impact.