I tried looking it up in the FAQ and I don't see it listed. What exactly is Backlash? How is it activated? Any help would be much appreciated.
When a character with Backlash wins a round the ability gets activated and affects you (the owner of the backlash character).
It's usually prejudicial for the player. See Beef, for example:
Backlash: - 2 Life Min 2
If Beef wins the round, the number of Life points of the player controlling Beef will be reduced by 2, or up to a minimum of 2. If the number of Life points of the player controlling Beef is lower than or equal to 2, then the ability will have no effect.