Hsu Hao/Original Timeline

Mortal Kombat: Deadly Alliance
Hsu Hao's superior, Mavado, gave him orders to act as a Chinese Secret Militant for the Special Forces and aid them in completely destroying the Black Dragon clan. Hsu Hao carried out his instructions without question and aided the U.S. Special Forces for years until the entire Black Dragon clan were seemingly eradicated, after the death of Jarek. Hsu Hao was called back to the Red Dragon headquarters at Charred Mountain but later received orders from Mavado to stay within the Special Forces HQ. He was then instructed to destroy their underground base and with it, their only means of inter-realm travel. He armed a miniature nuclear weapon and escaped through the portal just before it blew up.

As a result of his betrayal, his former superior at the Special Forces, Jax, who barely escaped with his life, had a score to settle with him. After Mavado captured and imprisoned Kano, Mavado sent Hsu Hao to kill Shang Tsung under orders from Quan Chi. On his way to Shang Tsung's palace he was cornered and killed when his artificial heart was ripped out by Jax.

Mortal Kombat: Armageddon
Hsu Hao inexplicably returned in Mortal Kombat: Armageddon, where he joined the Forces of Darkness in the battle of Armageddon. He fought Kenshi and later when the Pyramid of Argus emerged, he fought Johnny Cage when he only made it half way up the Pyramid. Hsu Hao and Cage then both fell off at the same time. He later died along with many other kombatants.

Biographies

 * Deadly Alliance: "A member of the Red Dragon, Hsu Hao's duty was to infiltrate the Special Forces and covertly guide them to members of the Black Dragon. Once the Black Dragon was seemingly destroyed, Hsu Hao was ordered to remain among the Special Forces ranks as an informant until further notice. That notice came when his superior, Mavado, ordered him to destroy the Outerworld Investigation Agency's ability to travel to Outworld. Hsu Hao would not dishonor his Red Dragon clan; he would complete his task at any cost. Hsu Hao gained access to an Ion Pulse bomb and infiltrated the heavily reinforced underground bunker that housed the techno-portals designed by the Agency. Barely evading Jax, Hsu Hao activated the portal to Outworld, switched on the bomb, and escaped into the portal before the Ion Pulse went off. The Agency was destroyed and with it any means for inter-realm travel from Earthrealm. Hsu Hao must now make contact with Mavado in Outworld to receive his next objective."
 * Bio Kard: "Hsu Hao's strength is matched only by his treachery. For years, this Red Dragon spy worked as a member of the Outworld Investigation Agency, alongside Sonya and Jax. Upon receiving orders from Mavado, Hsu Hao revealed himself as betrayer and destroyed the headquarters of OIA."

Endings

 * Deadly Alliance: (Cononical) "Hsu Hao reported to his superior, Mavado, and informed him of his success in destroying the Special Forces Outerworld Investigation Agency. Mavado then informed Hsu Hao of his next objective... It seemed that Quan Chi was proving to be a powerful ally and was willing to aid the Red Dragon in its quest for domination of Earth. In a show of good faith, Mavado agreed to destroy Quan Chi's enemies. The sorcerer suspected betrayal from Shang Tsung. There was evidence that Shang Tsung had allied with the two Oni known as Moloch and Drahmin. Hsu Hao's new orders were to eliminate the sorcerer Shang Tsung before the Oni eliminated Quan Chi."
 * Armageddon: (Non-Canonical) "Killed in the shockwave of Blaze's violent death, Hsu Hao's corrupt soul descended into the Netherrealm. As his soul began to regain a physical body, Hsu Hao became his true self: a demon of emptiness and desolation. Leading an Oni horde, he defeated Shinnok and his minions. He now sits upon the throne of the Netherrealm."

Character Relationships

 * Was introduced by Shujinko to Mavado.
 * Hired by Mavado to be a member of the Red Dragon.
 * Was sent to infiltrate the Outerworld Investigation Agency.
 * Seemingly destroyed the entire Black Dragon clan along with Sonya Blade and Jax Briggs.
 * Eventually betrayed Sonya and Jax and went back to Mavado, becoming the arch-rival of Jax.
 * Sent by Mavado to assassinate Shang Tsung.
 * Killed by Jax in Deadly Alliance.
 * Somehow was resurrected (possibly by Shinnok) and joined the Forces of Darkness in the final battle in Armageddon, but was killed again during the battle.