The elbow wouldn't be broken so easily, for Kawaii would react with himself turning his arm more clockwise while resisting the attempt to break his arm. Breaking an elbow in that position anyway wasn't easy, and he had the necessary leverage to resist it. But his eyes go wide when he sees that this arm of this guy....why the heck did it just make a metal-like sound? What the heck was going on? He couldn't have been....no, that couldn't be possible.
"No," he would say in silent shock as he heard the result of the attack. This was really....unexpected. Out of all things, this guy was somehow protected underneath his skin. What the heck was he? Did all along, Kawaii was only wasting energy against someone who was nearly impenetrable to damage? If that was so, then.....everything he had done.....
The right hand gripping his keyblade would be shivering as he slowly loses strength, letting Ultima Weapon fall to the ground, disappearing in a shining light. He would next let go of Oathkeeper, also letting it fall, but it disappears midway to the ground. That is when he would lower his head and shake it, finally saying words he did not ever believe he would come to say, but, he didn't have anything left in him. With such a handicap like this, there was no other way. He was drained of energy, and too tired to continue. Regenerating magic wasn't a problem, but it was the time it took to bring it back that was the disadvantage in it. He had a good run, but even he had to accept it was all over.
"I give up. You win..."