The P.T.W. Virus (Perfect Tyrant Warrior Virus) was an experimental virus created by Dr. Spencer to breed a powerful bioweapon for the glory of the Sith empire under the control of Tenebrae. For this reason, Spencer manufactured dozens of children that would be known as the Hellstrom Children and kept them under his supervision when they will soon be ready for the yet-to-be-made virus. However, with Tenebrae dead at the hands of the Ragnos Brothers, Spencer intended to cancel the production of the P.T.W. Virus, but Kain instead offered Spencer the oppertunity to create a grand empire of the future and insisted the elderly doctor to make the virus. Eventually, the virus was perfected and Spencer attempted to inject the virus into the Hellstrom Children upon its completion. The first of these children he injected into was Shang, with his baby sister being the last. Because of the virus's deadly process within the host's body and against the antibodies that try to counteract it, most of the Hellstrom Children died as a result upon injection, but only Shang and his sister survived the mutation. However, Shang's sister dies soon afterwards and this deeply scarred Shang into his very core. Shang eventually hunted down his creator and, upon learning the truth behind his creation and purpose, killed Spencer and avenged his sister's death and the rest of the Hellstrom Children's.
The P.T.W. Virus has various abilities that can be granted to the host, and most of these powers first begin of the body and eventually to many other traits. The injected host possesses superhuman strength, speed, reflexes, flexibility, senses, endurance, durability, intelligence, along with instantaneous regeneration and immortality. The host is also granted the power to awaken the Spiral Force within themselves and utilize it without effort. Also, the host's eyes are changed into a blood-red iris with slit pupils like a cat.
However, the only vulnerability to this virus's host is how much damage is applied to its heart and should the host suffer too much harm, they will die a permenant death. Also, despite possessing the ability to heal and regenerate, Shang still got a scar of his face by Fredrick from their first encounter, but this could be because of the Black Plague Virus that was kept dormant inside the Black Plague Hunter that allowed Fredrick to inflict a wound that would remain a scar.