Wraithkin, also known as The Taken, refers to a group of people (the only ones known are Athosians) whose ancestors were culled but spared from death, and who later possessed extra-sensory abilities. Charin was the only surviving member of the Athosians who remembered stories of the Taken, and eventually passed on the knowledge to Teyla Emmagan.
According to the legend there were a select few individuals who were returned to a planet in the Pegasus galaxy. Many believed it was a gift from the Ancients that their loved ones returned, but many others feared them, as those who returned began to behave strangely, spoke of hearing voices, and some even became violent and murderous. Eventually, the villagers of this world turned on the Taken, killing all but a few.
The ones that had survived were ostracized from the community, but left through the Stargate and passed on the "gift" to their children. The only known planet where Wraithkin settled and mixed with the inhabitants is Athos. However, presently very few Athosians have the abilities of the Taken.
Teyla Emmagan and the First Atlantis Reconnaissance Team discovered, in 2005, that it was because of a Wraith who was studying ways to enhance the feeding process so that humans would essentially become "tastier" to them. He was doing it against the wishes of the other Wraith, which was why he was doing it in secret. Later the Wraith conducting the experiments realized that he was enhancing his enemy with Wraith abilities and eventually gave up on the experiment. The Wraithkin all possessed the ability to sense the Wraith's presence and Teyla, once she learned she could do it, and with some help from hypnosis, figured out how to use her abilities to telepathically link to various Wraith. Teyla was also vulnerable to being possessed by Wraith, but in one instance, with her telepathy bolstered by her unborn child, she was able to take control of a Wraith Queen's body instead. Teyla also discovered the ability to control Wraith technology such as a Hive ship or presumably Wraith cruiser which required Wraith telepathic controls to work. However, when not pregnant with her son who was also Wraithkin, Teyla found it difficult and exhausting to pilot such ships. (SGA: "The Gift", "Halcyon", "Misbegotten", "Spoils of War")
After receiving training from Guide when she posed as his Queen, Teyla became more adept at using her mental powers to the point of having the strength of a Wraith Queen. She grew capable of piloting Wraith ships and killing Wraith with her mind by stopping their body processes. She later understands that before she lacked experience and feared her abilities so she didn't embrace them. Once she did and after Guide's training, Teyla's telepathic abilities grew to the strength of a Wraith Queen. She was strong enough to kill Queen Death, a very powerful Wraith Queen just using her telepathic abilities. Through dreams and hypnosis, Teyla gained access to some of the Wraith genetic memory, specifically the memory of Queen Osprey, the Wraith Queen the scientist who created the Wraithkin was descended from. (SGA: "Legacy")
A Wraith named Thorn later explained to Queen Waterlight how the Wraithkin came to be: the scientist who created them mingled his genes with his test subjects, partially transforming them before releasing them to breed. As this was against the old ways of the Wraith, his own sister stopped him, closing his testing facility and destroying his notes so that no one else could follow in his footsteps. However, by that point, the Wraithkin had spread out to a dozen worlds with no way to seek them out or identify them. The Wraith scientist tried again so his sister was forced to kill him. According to Thorn, the Wraith believe that within five to six generations, the Wraith blood in the Wraithkin would become so dilute that they would possess no abilities and so the Wraith no longer saw the Wraithkin as anything more than an interesting matter. (SGA: "Inheritors")
In 2010, the Tau'ri encountered a Wraith worshipper amongst the Travelers named Dekaas who revealed himself to be Wraithkin. Unlike the Athosians, his people didn't embrace Wraithkin and instead offered them up as tributes to the Wraith. Deekas was one such Wraithkin who was treated like this. (SGA: "The Third Path")
Due to their Wraith DNA, the Wraithkin have access to a number of Wraith-related abilities. Most require concentration, training, experience and occasionally outside help to use:
- Wraith Sensing: The most common ability amongst the Wraithkin is the ability to sense the presence of the Wraith when in proximity. Doctor Kate Heightmeyer suggests that this is a bleed-through effect of the Wraith telepathy their Wraith DNA gives them access to. Unlike the Wraithkin's other abilities, they do not require any sort of effort to sense the Wraith and instead do it automatically. According to Teyla Emmagan, amongst those who display this ability, some display it stronger than others. This is the only ability that the Wraithkin possess without consciously unlocking their other abilities. This part of Wraithkin Teyla Emmagan's abilities appeared to expand over time with Teyla able to sense that Ellia was different than the other Wraith and that another hive ship had dropped out of hyperspace and was very close to the one she was currently on. This sense is stated to extend for miles and a Wraithkin can sense if a Wraith is further away or has moved much closer. However, if the Wraith are in hibernation, the Wraithkin are not able to sense them. (SGA: "The Gift", "Instinct", "The Hive", "Submersion", "Infection")
- Access to the Wraith Telepathic Network: A Wraithkin is able to access the Wraith's telepathic network and access the mind of Wraith in relatively close proximity. While in this state, they can see through the eyes of the Wraith they connect to and listen in on everything nearby Wraith are saying. They can also use this to pass messages of their own to the Wraith. (SGA: "The Gift", "The Siege, Part 3")
- Wraith Mind-Linking: Wraithkin can connect directly to specific Wraith when in proximity. Depending on the level of the Wraith's strength, they can potentially read the Wraith in question's mind. While Wraith are unable to take control of the Wraithkin from a distance unless they have initiated a link first, at close-range a Wraith has demonstrated the ability to establish a link and take brief possession of a Wraithkin, albeit more like hypnotizing the Wraithkin than a full possession and only giving them simple commands. The same Wraith was able to open a link with the same Wraithkin across a distance of 10,000 light-years, a farther distance than Wraith are usually able reach and was able to disguise himself as someone else. However, the Wraith in question's abilities were enhanced by having become a Human-Wraith Hybrid at the time. An extremely powerful Wraith Queen demonstrated the ability to take control of Wraithkin Teyla Emmagan's mind and body, successfully posing as Teyla. However, Teyla needed to open her mind first and when fully prepared, was able to even plant a false memory for the Queen to find as a trick. (SGA: "The Siege, Part 1", "Michael", "Submersion", "The Kindred, Part 1")
- Wraith Technology Control: Wraithkin are able to control Wraith technology that usually requires a Wraith to control such as a hive ship or a Wraith cruiser. Inexperienced users will have a much harder time performing such a task and will only have limited control and find it exhausting, but with proper training in their Wraith abilities they can perform such a task with much greater ease. (SGA: "Misbegotten", "Spoils of War", "Legacy")
- Wraith Technology Immunity: While all of the other humans who encountered the Wraith mind manipulator were negatively effected, Wraithkin Teyla Emmagan proved to be immune to its effects. (SGA: "Phantoms")
- Empathy: If a Wraith is feeling a particularly strong emotion in proximity to a Wraithkin who have accessed their full abilities, they have occasionally displayed the ability to sense these emotions. During the Battle of Atlantis, Teyla Emmagan was able to sense the Wraiths fear that word of the human victory against them would get out and inspire other human worlds, telling Doctor Elizabeth Weir that at such close proximity, it was easy for her to sense this. She was also able to sense when a Wraith Queen was upset by the appearance of a second hive ship to join her culling, describing the Queen's feelings in detail. Later, when Michael was holding her captive, Teyla sensed his fear when the Atlantis team came to rescue her, though Michael called it "concern" instead. (SGA: "The Siege, Part 3", "The Hive", "The Kindred, Part 2")
- Possession: Working together, two Wraithkin can take control over a Wraith as powerful as a Hive queen. However, this requires intense concentration and leaves them vulnerable if that concentration slips even slightly. While possessing the Wraith in question, the Wraithkin are able to both control their movements and speak through them. (SGA: "Spoils of War")
- Wraith Telepathic Communication: After being trained by Guide, a Wraithkin displayed the ability to telepathically communicate with nearby Wraith without the need for linking with their minds. This ability was limited to telepathic talking and did not feature an exchange of thoughts or images beyond what was said telepathically. (SGA: "Legacy")
- Wraith Genetic Memory: The Wraithkin can access the genetic memory of the Wraith Queen Osprey that the Wraith scientist who created them was descended from, similar to a Wraith Queen's ability to do the same. However, this is not easy to accomplish and is only known to be consciously done through hypnosis. (SGA: "Secrets")
- Biokinesis: After extensive training from Guide, a Wraithkin displayed the ability to mentally stop a Wraith's biological processes similar to a Queen, killing them. They were even able to kill a Wraith Queen in this manner. (SGA: "Legacy")
- Illusion: The Torren John Emmagan from 2029 possessed the ability to create illusions capable of fooling Wraith not of Osprey's line. (SGA: "A Blade of Atlantis")