Mystery

Thanks to Rain's first attack and the fact that the sea emperor received the order to do everything necessary to win, Seadrei was able to free a part of his body from the control of the human king when he got rid of the first part of his shoulder that had been frozen thanks to Rain's punch.

Seadrei realized that Rain's attack froze his entire area of the body, essentially freezing the blood that had entered his body as well. When he dispelled the ice, he also dispelled the blood… when his arm was frozen again, he did the same thing and then he obtained full control over his arm and it was his dominant arm. Thanks to that, and the spear, he began to use the water in his body to expel the blood that had invaded it.