

With the use of the Tenno, the Orokin managed to turn the tide of battle. They were trained in the old ways of battle and given conduits that could withstand, channel and amplify their power. In desperation the Orokin utilized the survivors of the Zariman Ten Zero incident, to whom the Void had gifted immense power, to fight back against the Sentient threat.

With their advanced adaptability they were taking over the most sophisticated Orokin technology, and gradually gaining powerful resistances even to the most advanced of Orokin weaponry. However, the sentience they had gained also caused them to realize that their creators would lay waste to the Tau system as they did with Earth, and thus they returned to the Origin system to wage war with the Orokin. Theoretically, this would have left them stranded in the Tau system once they had finished their purpose. The Orokin crafted them with the ability to adapt to any sort of damage that they would encounter as well as the ability to replicate from damaged components, however the Void was "poison" to them, later revealed to interfere with their adaptation and replication. The Detron Crewman's memory imprint seems to suggest that the Sentients were originally developed as terraforming tools bound for the Tau system. Sentient remains on Earth, as shown during the Natah quest Orokin Era All Sentients deal Tau damage, alluding to their home system. Coupled with their own innate abilities, they proved to be a formidable threat for the Orokin Empire, almost leading it to its downfall. As their name suggests, they inadvertently gained sentience. For this purpose, and against the misgivings of certain Orokin Executors, they were gifted with an extreme degree of adaptability and resilience, bordering on true self-determination.

Originally suspected to be a truly alien race (whereas the Orokin, Grineer, Corpus and Tenno are all human or trans-human variations originating from Earth, and the Infested are a successive mutation of them), memory imprints provided by Cephalon Simaris revealed that they were originally created by the Orokin as terraforming machines, to be sent to the Tau System. The Sentients are an artificial race from the Tau System that were the chief enemies of the Orokin during the Old War.
