LogFAQs > #934796870

You've already seen that characters have crafts, that cost CP to use. They also have like a super craft, S-Craft, that requires a minimum of 100 CP to use and spends it all, with an additional boost if they are at a full 200. S-Crafts are unique in that you can use them even when it isn't that characters turn, which is S-Break. Breaking the turn order to use their S-craft. It's great for stealing good turn bonuses like sepith up, crit, str up, or whatever else and making sure bosses don't get it. They have a relatively lengthy delay before that character will get to act again, so use them wisely.
Attacks and crafts have a chance to "unbalance" an enemy, doing so gives you the option to let their link partner hit the target. Every character has attack types associated with them, Slash, Thrust, Pierce, and Strike, and ranks for those types. Enemies have weaknesses to those types, exploiting it will increase the chance of unbalance.
You should eventually be able to freely swap who is linked with who.
It should explain things more as you go along. The start just throws you in to try to get you hooked before it goes through the maybe somewhat lengthy introduction things.