Er not a video no but it's easy.
It's basically a "get out of combo" card. You can only use it once per match.
You have to wager how much meter (energy) to use.
If both players wage the same, then nothing happens they just bounce off each other.
If the defendant wins, he gains health back, if the attacker wins, he deals a lot of damage.
Saving meter is a crucial part of the fights so it always keeps you guessing what the opponent will do.
Thanks. I think I just don't understand which face button you push and does it change if you're on the player 2 side? Maybe this will be covered in a tutorial?