You can defeat Braig in Kingdom Hearts Birth By Sleep, Braig is the original persona of Xingbar from your Kingdom Hearts. His fight ensues much like Xingbars, but without reaction commands. Follow the simple steps below to kill the Braig when you are playing as Terra.
Prepare your character for your fight. You should be above 10 because Trinity Armor fight is before this and the Trinity Armour fight gave you these points).
Be sure to have a Block. This command is key to the battle.
Block Braig’s shots back three times to do damage and force the loser to come to you, or you could keep dodging bullets. At the start of the boss fight, Braig will warp to a high point and will shoot at you.
Continue to block all the remainder of the shots that Braig throws at you.
Wait until he needs to reload and go all out with combos.
Dodge the big bullet that Braig will try to throw at you. However, it won’t be easy. Braig’s largest shot that can’t be Blocked.
Braig has 600 HP. It should take some time to kill him.
Note
Using magic helps. The only magic you should use is Cure (a/aga), Fire (a,aga), and Blizzard.