|“||I am the real Master of Black X. I control everything. I rule every region. You shall die!||„|
|~ Boss X|
Boss X is the main villain and final boss of Red's storyline in SaGa Frontier.
Dr. Klein thought he is in control of Black X organization: He couldn't be more wrong.
Boss X is a strange creature on a huge robotic body, and the true leader of Black X. His past is a complete mystery. It is also unknown how Boss X came to be the leader of Black X, as the organization was led by Black Cross before him. He is fought inside Black X's base, after Alkaiser defeats the Four Emperors sent by Dr. Klein. Annoyed by Klein's repeated failures on removing Alkaiser, Boss X shoves him away and decides to fight Alkaiser by himself. However he also ends up being defeated, and with his defeat Black X is ultimately finished and Red avenging the death of his father.
Boss X seems to prefer to keep his leadership of Black X a secret. That said he does show a high opinion of himself by claiming he's in complete control and that he can defeat any foe he fights: a claim proved to be wrong when Red took him out.