evil castle room ideas?

Lots of huge mansions have sitting rooms where people just sit and socialize. Or I suppose in this case, discuss nefarious plans. A courtyard, too. Personally, I'm a fan of putting the courtyard in the center of the building by deleting the ground and ceiling above it to make it outdoors, but it could be outside the main building, too. Guests quarters can range from just a bedroom to a whole separate building. A trophy hall. Depending on what sort of evil, you could showcase things you've stolen, like for example, giant crystals, which can be found in debug using the bb.showhiddenobjects cheat.