Onyx is a powerful stack-based, multi-threaded, interpreted, general purpose programming language similar to PostScript and Forth. It can be embedded as an extension language into other applications, and was designed to have a small memory footprint. It is among the smallest embeddable interpreters available.
When activated, this causes one opponent who can see the crystal master to make a Will save (DC 10 + 2 per embedded gem + key ability modifier) or become shaken (see page 300 of the Dungeon Master's Guide) for 2d6 rounds. This ability can be used a number of times per day equal to the number of embedded gems.