The demigods needed to find you, at any cost. Percy had completely lost control, his anger had gone to his head on an absurd scale, as if all the anger he had stored was coming to the surface. He was furious like a heavy storm, and he was fighting like a demon. He didn't stop, he was using his full strength. He never used his full strength.
He had killed all the monsters that were trying to enter the camp, that is, he had killed thousands of monsters in less than two hours. Percy had clenched his fists so hard that his knuckles were white, his eyes burned with hatred. The situation was so serious that Zeus himself had come down from Olympus to see what had happened. Percy's attack was so great that it had messed with the balance on Olympus.
"I had to submit to every mission I was given, every challenge, every obstacle. And I succeeded in every one. And for what?" he growled, anger dripping from his voice.
Percy's anger coupled with how powerful he was formed a hostile and dangerous combination, for now the sea was stirring behind him. The skies turned gray and a storm was beginning to form. The 7 seas were being influenced by Percy's hatred, which caused Poseidon to appear.