Here's a video I recorded; it shows some pretty cool stuff that can be done off of a meter burned Empty Void. Extremely impractical and a huge waste of meter, but I thought it looked awesome.
There are a bunch of more damaging Empty Void combos that use less meter - mostly 2 meter combos.
EDIT: Here are some more practical setups. I feel like the second one is the BnB of these Empty Void combos. Activate Demon Stance and use these if you're getting zoned fullscreen! :] Let them know ain't nobody got time for that!
More can be done without demon stance MB DB2. If the opponent uses a projectile closer to you, you can just use 1 bar for Empty Void. I can't record those right now because I had to use two controllers by myself to throw the batarangs.
I can't switch controllers fast enough if Batman's too close.
MB Emtpy Void Down, B3, JI3, F222, DF2 for 39% if they are close enough for only 1 meter! This is really practical and nasty. :] Maybe later in the week my boyfriend will help me record that.