Out of curiosity, will Kye's hair-piece be sold in the shop, or will you at least give us instructions on how to make one like it?
It'd be really hard to sell his hairpiece in the shop for a few reasons, but mostly that it might get broken in shipment, since the horns might pop off fairly easily. I've been super gentle with it because I don't want to push my luck.
But here are some instructions for how I did it, if you're interested:
First, take this hairpiece (in black), which can be found in a few Ninjago sets. You'll need a pair of these horns (standard short LEGO horns) and these horns (BrickWarriors crescent horns, which Scorp sells here on the site). I chopped both of them just a little shorter to fit on the hairpiece, but mostly just to get rid of the nub on the bottom, then painted them dark tan. Paint them and let them dry before you try putting them on the hairpiece.
Then, get some crazy glue and stick the four horns on one at a time (I put a dot of glue on the hairpiece and stuck the horn onto it). Be sure to press the horn and hairpiece together really hard and hold it there for several seconds, or it's not gonna stick. It took a few tries to get them all on right, but I was super happy with the result.