Actually he's not... He just didn't care to elaborate.
What you would do is have someone get thier limit break, more attacks the better chances of pulling it off...
You go into battle with one support character, one dead character and one character with his/her limit break. The two characters that are alive will continuously give hero drinks to the character with his limit break and after enough hero drinks the character with the limit break will use it. Hero drinks will cause the limit break to keep repeating. Hit enough times and Emerald is dead.