Glowing Soulcaster Wristband - Inspired by the Stormlight Archives

I'm listening to the audiobook verion of Stormlight by Brandon Sanderson while working on things, and woke up this morning gripped with the inescapable need for a Soulcaster of my own.

From Wikepedia:

Soulcasting is a practice where objects are changed from one form to another. It has been shown to turn rock into smoke, purify the blood from poisons, and create food, and it has many other uses. Soulcasting is done by means of a device called a soulcaster that is powered by gems imbued with Stormlight. The type of gem placed inside the soulcaster determines what the caster can transform. With each use there is a chance of the gem cracking and being destroyed, especially when a large amount of matter is changed.

I think that sounds like a pretty useful thing to have.

So without further ado, I busted out the big box o' steampunk junk and the soldering iron, pulled out a few neopixels and an arduino micro controller (that's where the magic comes from) and came up with this lovely thing.

It's got three glowing gemstone spheres, set in brass for stability and maximum power transfer.  The straps are soft suede leather and it closes with two ornate brass buttons.  

The gemstones glow quite brightly fading between all the colors in the rainbow.  And of course, when I'm using it to transmute one kind of matter into another, they flash with a searing brightness.  

This thing is delighting me a whole lot.  It's also going to make a fantastic steampunk costume accessory.  What kind of mythical creature might steal and wear a soulcaster?  Are they of use to mermaids or fairies?  Maybe to this Steampunk Fairy.   What would you transmute with your very own soulcaster?