If you are like me, you see Ferra/Torr as one of the most interesting new characters. The oddball pairing is a fresh start for their species in Mortal Kombat. Unfortunately, however, the lack of information on them makes it hard to truly know anything about Ferra/Torr. After studying the Mortal Kombat X game, I've prepared a list of things we DO know so that origin theories are easier to formulate. If you find any of these helpful, please post your own theories below.
1. The Tarkata Connection
Source: During an intro dialogue between Mileena and Ferra/Torr, Ferra says, "We eat Tarkatans before." Furthermore, Ferra/Torr were picked up from the Tarkatan wastelands, which is also where they return in their arcade ladder so that Ferra can begin the Great Transformation.
Source: When questioned where they are from or how old she is, Ferra responds with, "We no remember." Considering the fact that their species has riders evolve into brutes over time, we can safely assume that Torr should know the answers to these questions. Since he doesn't, though, something must have caused his memory to go blank. Interestingly enough, Quan Chi seems to know something about their species, as he says there were once many like them.
3. Shang Tsung's Hand
The biography of Ferra/Torr states that Shang Tsung could have cursed the two beings to be bonded as one. This, while intriguing, causes confusion. Shang is a powerful and capable sorcerer but, seeing as how the ending says their race is naturally bonded together, cursing an entire race seems to be a tad bit out of his reach. When we look at the biography closer, it says they are, more than likely, members of a forgotten race. Shang is brought back into the equation when Kitana assumes they are one of his flesh pits creations, in addition to Quan Chi knowing about their history. As he and Shang worked with one another in both timelines, it is indeed possible that they shared knowledge with each other, whether for bragging rights or educational reasons.
Side points of information we know but may not have a clear understanding of just yet:
-Ferra/Torr has an affinity for eyes
-Ferra has a limited use of the English language, demonstrated by her bad grammar and vocal patterns
My theory is as follows:
Ferra/Torr's symbiotic race originates in Outworld. They were from a warrior culture and shared their land with the Tarkata, whom they struggled to maintain peace with because of their savage nature. After battling them for a long period of time, the land they shared became a barren wasteland. The Tarkata, having gotten the upper hand in terms of deaths, were able to force the remaining members of Ferra/Torr's race out, turning them into homeless wanderers. When Raiden travels back in time, the memory of Ferra/Torr is impacted because half of their respective souls gets lost in the time spasm and seized by Shang Tsung, which causes them to forget their history.