M'Nai was the son of two agents of Fu Manchu, the infamous president of the Si-Fan, a secret society determined to conquer the Earth. When M'Nai was a young child, his village was attacked by British Intelligence, and his parents were killed. M'Nai was scarred by the assault, and Fu Manchu took him into his home. MNai was raised at Fu Manchu's fortress in China's Honan province, and wore a black mask constantly to conceal his scars. He became the best friend of Shang-Chi, Fu Manchu's son. M'Nai took the codename Midnight as he grew to become one of Fu Manchu's assassins. On one assignment, Midnight was sent to recruit the Chinese scientist Half-Face to the Si-Fan, but Half-Face refused.

When Shang-Chi turned against Fu Manchu, Midnight felt betrayed by one whom he considered his brother, and fought Shang-Chi to the death in New York. Their battle ended atop winch, and when Midnight fell from the winch, his cape caught on its hook and broke his neck. Moments before his death, Midnight was taken into the realm of Limbo, by Kang the Conqueror to serve in the Legion of the Unliving he pitted against the Avengers. After the Legion’s defeat, the true master of Limbo,Immortus, returned Midnight to his own time to meet his death.

Agents of the extraterrestrial Kree obtained Midknight's body and stored it on the planet Bodoni-20. Eventually, the scientist Kar-Sagg revived his brain and made a physically enhanced clone of him which retained residual memories and his full combat prowess, but he lost the capacity for speech. When the Kree needed an agent to oppose the Silver Surfer during one of their wars with the Skrulls, Kar-Sagg provided the clone, now christened the Midnight Sun. Although Midnight Sun was capable of battling the Silver Surfer, his lingering sense of honor in combat kept him from taking advantage of the Surfer.

Kar-Sagg believed that Midnight Sun's memories were holding him back and attempted to purge them, but Midnight Sun resisted this, determined to learn who he truly was, and fought his way to freedom from the Kree. Journeying to Earth, he meditated over his partial memories upon the moon. When he saw the Silver Surfer leaving the Earth after an adventure, he pursued him, thinking the Silver Surfer knew something of his past; but unable to speak, he wound up fighting the Surfer. This was finally broken up by the Inhumans, who lived in the lunar city of Attilan. When they learned of the Midnight Sun's plight, they welcomed him into their city to seek some means of communicating with him. Given the upheaval Attilan has endured in recent years, Midnight Sun's present fate is uncertain.