Turning the previous elf house into Stanengist was what enslaved the orcs, and made demonic incursion possible

(1) What’s up with the orcs?

Legends say that Wyrm told Clay to create the orcs, to address the imbalance between elves+dwarves and the newly-arrived humans. When war happened, elves+dwarves sent their orc slaves into battle against the humans. The humans raised demons in turn and won; the elves and dwarves went away and sulked; the orcs ended up free, and before they could calm down and consider “what do we do about our enslavers?” the bloodmist turned up and made everyone stay at home for 200-odd years.

But the Bloodmarch tells us that on the other side of the mountains, the orcs have always been free. So Wyrm and Clay didn’t create orcs as a slave race.

And why would they have? Elves and dwarves didn’t want or need a slave race for their everyday life; they’d both been happy doing their own thing for years, and it was precisely the arrival of disruptive, fast-reproducing surface-dwellers - humans - that irked them in the first place. Plenty of wise elves and dwarves would have counselled against creating orcs, because of what might happen if they lost the war: wouldn’t the orcs ally with the triumphant humans to destroy their creators?

And given that they did lose the war, we need to ask: (1) why didn’t the orcs wipe out the elves and/or dwarves in retaliation; and, failing that, (2) why didn’t the elves and/or dwarves try to enslave the orcs again?

(2) What’s up with Stanengist?

The first elves turned up, mapped the Forbidden Lands, then decided that they were done and they should retire to the stillmist and park their rubies in a communal thing where they could all be. Fine.

There’s a crown called Stanengist, and whoever wears it apparently gets to rule, although if you look at its stats it doesn’t let you do anything of the kind, and you’re better off keeping the rubies in the sword, sceptre and cloak clasp rather than putting them in the crown.

Also: has anyone actually ever worn Stanengist as a ruler? Yes, the first elves asked one of the first dwarves to forge it, but the whole point of that enlightened time was that dwarves and elves lived in separate harmony. There was no need to assert supremacy.

And: why is it that sacrificing Stanengist can seal the rift that demons currently come through? And not just in a “any sufficiently-powered magical item can probably do the thing” way; Stanengist can seal the protonexus permanently, with the implication that you can’t just open another rift later on.

(3) Theory: Stanengist is what enslaved the orcs, and made opening the rift possible

While the elves did indeed build the stillmist as a place where they could rest, and a modest circlet which could hold their rubies when they were tired of the flesh, it was always intended as (1) a home for the first elves where they could rest in peace, and (2) a way for them to advise whoever donned it from time to time.

Faced with the threat from the humans, the elves and dwarves decided they needed something very different, and reforged the circlet into an intimidating crown of power they called Stanengist. Previously elves, dwarves, halflings, goblins, orcs and humans lived separately in their own realms; the creation of Stanengist asserted one single ruler, to have dominion over all. Elves and dwarves agreed to abide by that rule, and as a first act of strength subjugated the previously-free orcs.

This powerful act of cruel magic sent a signal that demons can hear, so when Zygofer was trying to contact demons, the demons were already trying to get to the Forbidden Lands from the other side. The protonexus opened; demons found a cruel and powerful mage on the other side, so assumed it was him they’d heard, and Zygofer wasn’t aware of the creation of Stanengist so assumed he’d managed to open the rift all by himself because he’s awesome. (If demons ever said “something about this magic feels elvish”, Zygofer has already based his right to rule the Forbidden Lands on his elven heritage.)

And the elves and dwarves couldn’t enslave the orcs again after the war was over because nobody knew where Stanengist was after Merigall had nicked it.

(4) Why doesn’t Zytera know about Stanengist?

This also explains why Zytera doesn’t know Stanengist will drive him mad: in truth, he doesn’t know much about it.

At some point some elf or dwarf stood at the back of an army and very loudly said “look at me, I wear Stanengist, I’m going to win this battle”, and a bunch of elves, dwarves and orcs did indeed win the battle, but that just lead Zygofer to summon more demons (in truth it was the cruelty of Stanengist that summoned them but never mind).

Eventually the humans+demons won the war, Zygofer and Therania turned into Zytera, and only after a few hundred years of doing unspeakable things to unfortunate souls thought “wait, wasn’t there a crown?” - and that’s all he knows.

As to why Stanengist drives demons or demon-adjacent people mad, maybe it’s because it’s a symbol of the land that they’re not from? Its assertion of legitimacy and belonging is what attracted them, but precisely because - maddeningly - it’s one of the few things they can’t have. They can destroy it, yes, but never possess it.