https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1377341785
While playing around with the "Give Aspect" action, I found you can pretty much give the player anything in the game. As seen here, I've build myself a new dungeon core and a Gateway. Some interesting things I've found so far:

Building things like core, gateways, etc., are priced 100 gold, obviously not meant to be built.
Core will be black void tiles that can store gold, but when placed 5x5 will create the core. Attempting to "expand" your core will create void tiles and bug out. Unknown if its separate or shares health

Gateways seem to spawn fully in one tile.

You are unable to sell these rooms like normally.

Most defenses seem to have stats applied to them.
Ballistas are 500 gold, lock 15 mana, and even has a quote for it when its finished completed "Ballista complete".
Siege doors/gates also have high cost, but seem to bug out. They only need one tile to be built on, but still need the wall space. Claiming the land its built on after building will delete it.
Stone Sentinals are also available and costly, requiring 50 defense parts.

There are also a bit of Rituals and Spells that seem to be available, but I haven't had time to try them out yet.

While it's nothing that I see myself using at the moment, I'm sure someone could find ways to incorporate this into a unique map!