Now that the four of them have solved the riddle of the golden core, it's time to start the fight. The southern genius, the black tortoise, is the one who should be fighting, since he's the one with the "power of the void" . The two of them start to argue about who should win, and the southern genius gets more and more worried about who's going to win. The black tortoise says that he'll win, because he has the bloodline of the "black tortoise" , and he can use that power to bridge the gap between the two worlds. He's got the power to do that, too, since his body is made of the same stuff as the "golden core" !