It was the day of the fight , and both Percy and Ronan had not slept a wink the night before.
For Percy it was because he was nervous and scared about the fight , his mind running simulations of what could go wrong and how could he bounce back from the worst.
This was the single fight that he had planned a thousand times in his head, with every step of the plan having a plan B, C , D and E , with him planning the next step of each of those steps as well.
As he memorized Ronan's moves and his movements and his understanding of his brother as a fighter , he utilized every small detail to make his plans more and more refined to give him the best odds of victory.