Get up close to your opponent and throw your boomerang. Then do a strong sword slash or a spinning sword attack or a sword thrust or throw. If you throw your boomerang and then get close to your opponent so that it hits him from behind, it will be even easier to finish off the combo. It should also extend the damage level to under 50% as well.

Get up close to your opponent and throw your boomerang. Then do a low forward slash, jump, and finish it with a quick spinning sword attack.

Stand next to your opponent and do a 3-hit upwards sword attack, then an overhead slash, jump, and follow it with an upward sword thrust.

Get your bomb out but don't throw it. Then, throw your boomerang, throw the bomb, and finish it with a sword thrust.