Instead of creating somewhere new, or massively altering the politics of an existing settlement, I think Sibayad would be a great location for evil-doers of the surface to congregate, and scheme. Sibayad is such a cool place, it already has everything for a settlement, all it would need is a formalized Gov't, and the law pillars adjusted to reflect the new values. Unfortunately, right now Sibayad is little more than a place to do higher level writs, and hosts vacation homes for Cordorian nobles.
I think the only other thing it needs is a way to travel there from the UD, and I could be wrong and one already exists, but the only way I'm aware of to travel there is Captain whats-his-face in Crow's nest.
I know that a lot of this could/has to be done IC, but even if I started a Sibayad mafia, or something, but without admins involved very little would change in terms of the town structure.
I think there's quite a few cool ways this could go, maybe an evil cult takes control over the city, a mafia is formed, underdarkers who have been banished from Andunor seeking refuge, a lot of things.
Help me make Sibayad the wretched hive of scum and villainy we all know it can be
There's another similar thread on here, but that one got bogged down with history lessons and so I'm posting a more specific feedback here.