The "Skyward Dragon" move is one that lets you launch an enemy into the air with B and hammer X to do massive damage. You'll only get the B prompt this when your hit a certain combo (your fists will start glowing). If you take every opportunity you can to do this, you'll probably get this cheev by the time you finish the story mode.
However, if you're imaptient like me and want to grind it out early, you can also do this in the Arena Battle mode. The dragon-shaped power-up will let you run up to another player and instantly do this move. If you bring in a dummy account, run to their spawn point, and keep grabbing nearby power-ups (which respawn very fast) until you get the one you need, you'll be able to do 4-5 of these in every five-minute match.
Either way, this is a pretty straightforward achievement. If you have something to add, leave a comment and I'll edit.