Hsu Hao was a Red Dragon operative, that has infiltrated himself inside the Special Forces top secret Outer World Investigation Agency, led by Sonya Blade and Major Jackson Briggs. Once Mavado, his superior, gave Hsu Hao the order, Hsu Hao activated a miniature nuclear weapon inside the OIA's H.Q., and once it blew off, their underground base and their means to inter-realm travel were destroyed as well. Unbeknownst to Hao, Jax had caught on to his mischief and secretly followed him to Outworld, hungry for vengeance.
Later on, while the Red Dragon clan was working secretly for one of the halves of the Deadly Alliance (Quan Chi), Hsu Hao was ordered by Mavado to assassinate Shang Tsung. On his way to Shang Tsung's palace, he was ambushed and badly beaten to a pulp by an enraged Major Jackson Briggs. He showed the worthless traitor no mercy. Jax grabbed onto Hao's artifical chest implantation, began roughly twisting at the metal and tearing through his flesh with no mercy. Hao screamed hysterically in horrible agony as Jax laughed out loud and ripped his heart implant right out from his chest. Raiden himself narrates that this was indeed, a very painful way to go. Hsu Hao bled out right in front of Shang Tsungs's palace moments later, failing his mission and going straight to hell.
Hsu Hao's Armageddon
During the events of Mortal Kombat Armageddon, Hsu Hao was mysteriously resurrected from the dead to fight along side the Forces of Darkness in the final showdown of good and evil. It was likely Shinnok who resurrect the murdered Mongolian, since he was in charge of the Forces of Darkness.
Hsu Hao was revealed to be killed in the shockwave of Blaze's death in his own ending. He was then reincarnated in the Netherrealm as an Oni, where he would forever wonder the wastelands of hell and serve as a minion of the underworld.
Hsu Hao is only seen at the very beginning in the first issue of Mortal Kombat X's comic tie-in. Hao appears as a squad leader of Red Dragon mercenaries, and is seen chasing after an injured Kenshi and his son, Takeda. When they finally reach the duo, Kenshi yells for his son to run away and the crew of Red Dragon pummel the blind man to a pulp. Hsu Hao was very glad to follow through on his masters orders, screaming that Daegon commanded that Kenshi be executed. He was just about to finish him off, but Scorpion came to the rescue. Scorpion threw his spear right into Hsu Hao's artificial heart implant, and pulled him towards himself with all of his might. The mischievous Mongolian was then forcefully dragged across the woods until his face finally collided with Scorpion's fist, punching straight through his head. Chunks of brain matter and bone were sent flying through the back of his skull, even Hao's eyeballs were pushed out through the new gaping hole in his noggin. Hsu Hao will not return again.
Hsu Hao is quite an infamous character in the Mortal Kombat franchise. Not only is he despised by players everywhere, he is even hated by the developers themselves. John Vogel had said he wrote Jax's ending because he wanted to get rid of Hsu Hao and had no intentions of bringing him back. He wanted to get rid of this joke in the most sadistic way possible, and Vogel was all to happy to make him die in such a gruesome manner. However, due to the development of Armaggedon, which was going to have every character from MK, he had no choice but to bring him back to the roster, much to his dismay.
Now, Hsu Hao will never return again as he was now killed by Scorpion. Ironically Hsu Hao is Ed Boon's least favorite character with Scorpion being his most loved. Ed Boon had vocally voiced his hatred for Hsu Hao in several interviews, pleased about the unpleasant passing of Hao. When the alternate timeline story was launched in Mortal Kombat 9, Boon let fans know Hao would not be playable ever again, but did like Scorpion, so many came to the conclusion that Hsu Hao might be killed again by the yellow ninja himself when Mortal Kombat X was announced. The fan service was delivered, and Hao was brained like he should've been at birth in the very first issue of the Mortal Kombat X prequel comic book, not even making it to the actual game itself.