Core's final move wasn't anything flashy or powerful. It wasn't even complicated, a simple straight punch that raced toward Arad's face at blinding speed and with a harrowing amount of physical might behind it.
Arad had trouble understanding what part of this move made it a final move, something to finish the fight with, especially with the musician angels going crazy above them as if Core's punch would destroy the whole world.
But that was Arad's biggest mistake; he had spent the whole fight predicting Core's moves and actions based on the rhythm of the music they were dancing to, which worked, until now.
Core was about to give Arad an important lesson. Never take anything for granted; always expect the unexpected.
Core was a bard, and he had danced to the music this whole fight, all for the sake of this one final move. He didn't follow the music's rhythm, and that had thrown all of Arad's defences out of order, causing him to get smacked right in the face.