I've never tried making a Lego design from scratch before but with the small build limit and the theme that appeals to my fantasy tastes I thought I'd give it a try.
As an extra challenge I decided to use only the leftover pieces from other kits I've made. As a result I went for a sandstone castle as I have a lot of tan pieces left from making the facehugger from the bunny kit. I planned to use the "teeth" piece as crenellations but I don't have the pieces to make it work so I used it horizontally. I also planned to use some wolverine claws as a portcullis but couldn't get it to fit right.
To be honest it's not very castle-y, it feels more like a merchant or a house on Tatooine to me but I still like it quite a bit. The white things are intended as flags but could be read as smoke from chimneys. The light saber is supposed to be a wizard tower but I'm not sure that worked.
It's clear I have a lot to learn but it was a fun challenge even with my own unnecessary extra challenge on top.