Aelia has kept a secret from X and everyone else. She is a half blood. The half she hid was that of the Black heart race. A savage race of fox people who take pleasure in causing misery. X, being of the sacred fox race, which disowns outsiders especially Black hearts, terrified Aelia into thinking she'd be alone again if X ever found out. little did she know, X himself is a half blood, and was henceforth confined to the branch of his race. therefore, he doesnt care that Aelia's a Black heart.