Canary Cry is Black Canary's
ability. It charges automatically throughout the match—you will see the icon change from yellow to orange to red as it charges. Once it's red, it has charged to level 3.
Even at level 3, it doesn't do much damage, it's used mostly for it's great knock back. To get the final hit with it, make sure your opponent is very very close to death and doesn't block.
Tip: If you're doing this in a live match, you can hold in
as long as you like before releasing it during an opening, but beware: if your opponent lands a hit while you're holding
, you'll lose the ability to release it and your Cry charge will start all over at level 0.