Even as the rakshasa derided the king and his dynasty, Anaranya issued a curse that Ravana would meet his end by one of his descendants from the same dynasty. This curse comes true when Rama defeats Ravana.
Even as the rakshasa ridiculed the king and his heritage, Anaranya pronounced a judgment that Ravana's downfall would occur through one of his own relatives from the same ancestral lineage. This prophecy is realized when Rama emerges victorious over Ravana.