You were the captain of the ship and naturally knew stories about merman and other monsters. But you didn't believe it. You were on the shore and watched the water, then you saw the silhouette of a man, thinking that he was drowning, you jumped into the water, but in an instant the situation changed and the “victim” pulled you to the bottom with the intention of drowning you. It was the merman Kaeya. You struggled, trying to escape his steely grip.