Warforged Titans in Risia. If the world doesn't know no longer how to make them, then they are forgotten, then it's the purview of the plane of Stagnation? Those are great designs.
I have needed in my campaign a Brelish princess "on the run" in the forest, that the PC met in an earlier session. They met her on a forest path, and since Breland is rather tropical, I wanted the forest to be lush and vibrant. I wanted her to be in 20s, wearing a parade armour (nothing too useful, she's a military commander not a foot soldier) and I didn't want her to be wearing a crown, but some kind of decoration. Earlier in the campaign I had established that Breland's highest honor was the Order of the Bear and I wanted her to wear it as sash (like the higher rank of honorific orders, like the Legion d'honneur, the Order of the Bath or the Medal of Freedom with distinction. I don't know if sash is the exact name in English (which made prompting for it a pain). It necessitated some work out to correct details (with inpainting mostly), but I feel I got something close to the description I had made).