Oh, for those who don't know how the system works, it goes like this: you first walk around a bunch and when you find an enemy you try to attack it first. If you do, you get like the first strike but if the enemy attacks you first the opposite will occur. You only control your main character but you can assign tactics to up to three additional party members like full assault or heal/support.
Each party member has a "Persona" which is basically a set of skills that they can use depending on the Persona's level. Even though you party can have one persona per member, the main character can "switch" Personas or change his skill set. After your main character does his turn his party and enemies start to move. Some skills have certain attributes that certain enemies are vulnerable against and if exploited the enemy will be thrown off balance and the caster gets an additional turn. If all enemies are off balance the main character has an option to do an "All-Out Attack" which means that the party will gang-up on the enemies and deal absolute damage equal to their combined attack power or to "Relent" and just do one more thing. Well, thats the combat system I'm trying to make in a nutshell. If you don't understand, just go to Youtube.
It's what like I always say; All great questions end up in two places: God and the Internet.