the Brilliant Ivory Citadel

[icosahedron]

I'm not familiar with 'Exalted', so I may be missing some important ponts, but...

Apart from the stone walls, the shape suggested a Roman camp to me. Not what is conjured up in my mind by the titles 'citadel' or 'fortress'. Defence in depth is a watchword of most fortresses, and once you've breached those walls, there's nothing but useful cover inside.

Maybe you need some form of powerful keep in there, and a less regular shape? As a local headquarters for the undead, I'd expect something more gothic, but that's just me.

[Ascension]

I think that the main thing that you're missing is some cool patterns...these are pretty simplistic. While there's nothing wrong with that, you obviously want to kick it up a notch. Browse through the Mapping Elements section and follow the links for different pattern websites. There might be some in the Reference Material section as well, not sure. You could also just do a forum search for "patterns" or something. As for the little buildings, have a look at the Dunjinni user forums, there's a ton of cool lil roofs there.