Phobos is the main antagonist and final boss of Madness: Project Nexus Episode 1.5. He is the head of Project Nexus and is fought twice in the episode.
Phobos first appears in level [1.5-D], wielding only his binary sword and confronting Dr. Christoff when he discovers he has defected from Project Nexus. Using the binary sword, he can deflect almost every bullet fired at him and knock out any melee weapons used against him. However, once he is successfully hit by an attack, he will flee the room and tell Dr. Christoff that they will meet again.
He doesn't reappear until the final level, where he resides in the last room armed with the binary sword and a TMP. While wielding the binary sword, he uses it to block attacks. When he is using the TMP, he dodges attacks by performing very high back flips or utilizing his TAC-Bar. Despite his evasive skills, he is still vulnerable to Nexus bolts and cannot block them with his sword. Once he is killed, Jesus will say to him, "Goodnight, Phobos."