Demon Lords and Archdevils (in Ravenloft)

[Speedwagon]

I read up a bit on Van Richten's Guide to Fiends and thought it interesting how many fiends are 'smaller scale' than the usual power level in D&D. While I understand that this was done intentionally to preserve the horror (as horror is easier to pull off at level 2 than level 20), it got the gears turning for me. How would certain Fiends adapt to Ravenloft? What schemes would they pull to try and get out, or what would they scheme once they decide that this new misty realm has promise for suffering? To give a better idea, imagine this: Moloch, Fraz-Urb'Luu, Zuggtmoy, Zariel, Juiblex, and Levistus get wrenched out of wherever they previously were and are thrown into Ravenloft. How would you implement them into the setting? Would Fraz-Urb'Luu start messing with the Church of Belenus by acting as an avatar to mess with Elena Faith-hold the way Malistroi interacted with Yagno Petrovna? Would Zariel have interesting interactions with the Church of Ezra's more overzealous sects? That kinda stuff.

[Rock of the Fraternity]

A bit off-topic, but I went the opposite route when I created the Red Haubt and Roe (see mistipedia).
These are demons who were in a servile position, but have room to grow stronger. To them, Ravenloft is/was a safe haven from powers that might otherwise halt their growth or use them to destruction; a place of surprising freedom, for all its limits.

A lord-level fiend, though, would probably fly into a rage and try to tear the place apart so they could get out. I imagine their reality wrinkle resembling a nonstop natural calamity.

[Mephisto of the FoS]

Would Zariel have interesting interactions with the Church of Ezra's more overzealous sects? That kinda stuff.

I am not very familiar with D&D Archdevils and Demon Lords but the above sentence reminded me of these movies.
The Devils (1971) set in In 17th-century France (good for a Dementlieu or Richemulot setting) and The Nun and the Devil (Le Monache di Sant'Arcangelo, 1973 ) an Italian, erotic, nunsploitation movie.

I imagine their reality wrinkle resembling a nonstop natural calamity.

I agree...

Since the the Dark Powers were never defined prior to 5th edition, they were only described as powerful enough to block priests from their gods (at least some powers). Although it is also not defined if the powers given to priests in Ravenloft are channeled from their gods, in most Ravenloft novels outlander clerics feel they have lost connection to their deities.

But if such they would need a lot of focus(?) to trap a powerful entity, that happened with Vecna and didn't last long and could have tore apart the Demiplane (at least that is what the summary of Vecna Reborn writes, never bought it, I am not a big fan of Vecna beig more of a dark fantasy character and also Azalin is the king of the dead and the only ultralich in my Ravenloft).

I believe the Dark Powers would probably avoid attracting very powerful entities. For instance in my QtR article the Conch Shell of Sorrows, I have written that this is an artifact created by a drop of blood belonging to Dagon, the Prince of the Depths, who is a primordial obyrith, and a demon lord (off course this is non-canon). I speculate in the article that the Sea of Sorrows was created as a reality wrinkle to this artifact. When the Grand Conjunction collapsed and the Dark Powers begun re-imprisoning everybody, they managed to confine the Demon Lord's essence reality wrinkle only in a small part of the Core but with major changes to the lands affected and the Sea of Sorrows remained as the domain the captain of the Relentless.

It all comes to each DM's definition of the Dark Powers and Ravenloft. Is the Demiplane a place were evil beings are imprisoned by the Dark Powers out of a weird sense of justice (condemning hundreds of other people with them in their domain) or to channel all the frustration created by their curses as well as the agony of the people suffering in their domain, as emotional resonance to empower them for some plan the Dark Powers have about the multiverse? I haven't defined them even to myself for instance, I am in a constant debate with myself on their nature

[Rock of the Fraternity]

What do you mean, "or"?

[Mistmaster]

What do you mean, "or"?

I have ditched Dark Powers totally in favour of semi-sentient Mist.

[The Lesser Evil]

I read up a bit on Van Richten's Guide to Fiends and thought it interesting how many fiends are 'smaller scale' than the usual power level in D&D. While I understand that this was done intentionally to preserve the horror (as horror is easier to pull off at level 2 than level 20), it got the gears turning for me. How would certain Fiends adapt to Ravenloft? What schemes would they pull to try and get out, or what would they scheme once they decide that this new misty realm has promise for suffering? To give a better idea, imagine this: Moloch, Fraz-Urb'Luu, Zuggtmoy, Zariel, Juiblex, and Levistus get wrenched out of wherever they previously were and are thrown into Ravenloft. How would you implement them into the setting?

I'd look at this from precedence. I see three existing points of comparison:
1) Gwydion
2) Ebonbane
3) Vecna

All three came to Ravenloft under pretty special circumstances. The Dark Powers didn't even technically call Gwydion into their realm, he came in after the fleeing Arakans who created an exit out of the shadow realm that trapped him. And he was on the precipice of getting here, the Arakans slammed the Obsidian Gate between Ravenloft and Gwydion's shadow realm. And the Dark Powers still needed or desired to fabricate a whole domain out of Gwydion's reality wrinkle.

Ebonbane/Lussimar and Vecna were both trapped/called to Ravenloft by the Dark Powers, but only under special circumstances. Lussimar was bound by a mortal forged sword, and there was also Kateri Shadowborn's ghost to help keep him in lie. Similarly, Vecna could only be trapped when he manifested on the material plane to tussle with some of his old Oerth enemies. And they had to keep him trapped in avatar form to boot.

So with the above said, I would probably introduce any big name new players in weakened forms or Sealed Evil in a Can sort. Perhaps for example, one could be the unnamed escaped vestige from the Amber Temple mentioned in Curse of Strahd, for example. I would make it an obscure or homebrew fiend lord, though, and, as a vestige, the fiend lord would have to do a considerable amount to regain all of its former power/glory.

Would Fraz-Urb'Luu start messing with the Church of Belenus by acting as an avatar to mess with Elena Faith-hold the way Malistroi interacted with Yagno Petrovna?

No, I would avoid using Fraaz-Urb'Luu in the Shadowlands, at least directly. The Shadowlands has at least one big time fiend player (Ebonbane/Lussimar) and maybe another, depending upon how you interpret Theokos (from the Book of Sorrows). And the Church of Belenus is already walking the path of darkness Yo me, it seems like there's more lucrative targets out there than a cramped space of the Shadowlands where the good is already dying out.

Would Zariel have interesting interactions with the Church of Ezra's more overzealous sects? That kinda stuff.

Depending on how you interpret the Blessed Army of Ezra, something like this may already be happening. In brief for those without Heroes of Light, in this plot thread the Mordentish branch has been gathering an army to secretly attack the Nevuchar Springs sect on the fear/prophecy that they have been subverted by a fiend masquerading as one of the clergy.

[tomokaicho]

The Gates of Hell from Dicefreaks describes how archfiends wound the land by their very presence, and this is on the Prime Material Plane. In Ravenloft, the presence of an archfiend would be gaping, open wound on the land and the metaphysical environment, triggering an outpouring of depravity and corruption upon the inhabitants.

The Gates of Hell is highly recommended.

[Baron Von Stanton]

Ravenloft is a very resonate land. If an archfiend or similar near-godlike being of evil were to enter the demiplane, it would form a reality wrinkle so large, it would essentially create its own domain, i.e., what happened when Vecna, Ebonbane and Gwydion entered the demiplane.

Furthermore, as Vecna happily demonstrated, if the entrapped archfiend isn't further impaired while trapped, there's probably very little the Dark Powers can do to prevent the archfiend from figuring out a way to escape.

[alhoon]

To be honest, I had an issue with both Vecna being trapped and the way he got out after being trapped. If he escaped during the Grand Conjuction I would understand. Still, trapping a deity is a bit too far for Ravenloft.

Anyway, back to Archfiends, I agree with the "what happened to Ebonbane and Gwydion" camp. The DP are sufficiently powerful to trap such a creature.

[Mephisto of the FoS]

What about the Iron Flask of Tuerny the Merciless, can it entrap an archfiend?

[Baron Von Stanton]

What about the Iron Flask of Tuerny the Merciless, can it entrap an archfiend?

Yes, it was used to trap Grazz't once by Tuerny, himself, only for Grazz't to eventually break free in order to drag Tuerny into the Abyss and turn him into a dretch.