help i dont know how to do this stuff

i am stuck how do you get that limit thing wher you make your own limit and that new game pluse thing i dont know how you do that

to make your own limit you gotta buy it in the shop form the challenges in story mode

I thought you just unlocked it in that mission at the start when ummm,,,, I can't remember his name now,, anyway he gives you a thump that lowers your health
then you hold down the attack button, you glow abit roxas says "you're finished" and then swing like mad (I never used it until I think xigbar offers something if you kill 50 with final limit,