In Total Drama (I can't remember which one), Harold had two Yo-Yo's that he tied together and called it a NumYo. This may have been cool to you or just some lame thing on television. For me, it sparked some creativity in my head. So if you've been searching the internet to make one of these, then this is probably the only thing you've found and will find. Trust me, I've looked. Anyway, this is really easy and I encourage you to step out of your comfort zone (if you have one) and make this. I only spent $2. :)
Step 1: The Yo-Yo's
You're gonna want to get two Easy Yo-Yo's or that sort of thing. This way, you can use the NumYo without unraveling it.
Step 2: The Conecters
In Total Drama, Harold tied two Yo-Yo's together, but the kind we'll be using have plastic rings on them so that they don't get lost in the ball. What you need are two sandwich ties. Just use these to tie up the two loops
Step 3: Done!
Now you have a NumYo that you can use in fake Martial Arts. Have fun with it, and make sure you don't have a jerky friend around who will throw a stick at you.