Helenus

In Greek mythology, Helenus (/ˈhɛlənəs/; Ancient Greek: Ἕλενος) was the son of King Priam and Queen Hecuba of Troy, and the twin brother of the prophetess Cassandra. He was also called Scamandrios. According to legend, Cassandra, having been given the power of prophecy by Apollo, taught it to her brother. Like Cassandra, he was always right, but unlike her, others believed him.