Davos was the leader of the Vedeenans with a daughter named Linara. Due to having precognition, he was looked to as a leader by his people and at some point, developed a terminal form of lymphatic cancer. When a Wraith hive ship arrived to cull Vedeena, Davos saw the ship's arrival and warned his people in time to seek shelter, resulting in the loss of no Vedeenans to the Wraith.
When Lt. Colonel John Sheppard's team comes to Vedeena to find out anything Davos might know about the missing Athosians, Davos predicts their arrival and sends a greeting party led by Linara to meet them. Upon the team's arrival, Davos is able to sense McKay's skepticism and shows McKay a vision of the team being ambushed by the Wraith. The effort exhausts Davos due to his weakened state and Atlantis sends Doctor Jennifer Keller to examine him. Keller is able to determine he has a form of lymphatic cancer, but is unable to tell his prognosis or the source of his powers with the equipment she has so Davos is brought to Atlantis.
On Atlantis, Keller determines that Davos' condition is terminal and all she can do is ease his symptoms. While on Atlantis, Davos meets with Colonel Samantha Carter and shares with her a vision of the apparent destruction of Atlantis by an Aurora-class battleship. Davos later meets with Teyla Emmagan on an Atlantis balcony and she asks him about her people. All Davos can tell is that they are alive and are shrouded by darkness. While Davos knows Teyla will keep searching, he suggests that she shouldn't while pregnant, a fact she has not shared with anyone. As Teyla takes Davos to meet with Carter at his request, Davos suddenly collapses and shares with her a vision of what appears to be Sheppard destroying a hive ship with drone weapons. Following his collapse, Davos is relegated to a bed in the infirmary where Carter visits him for insights into his visions. Davos informs Carter that his visions are never wrong and can't be changed, but suggests that they do not occur as they are interpreted. Davos suggests that the future is shaped by the character of those who shape it and states his belief that the galaxy is at a crossroads with the future of many depending on the actions of a few. Shortly afterwards, Davos develops breathing trouble and dies with Keller and Linara at his side.
The morning after Davos' death, Linara takes his body back to Vedeena to be buried in Vedeenan custom. While Carter and Sheppard are disturbed by Davos' prediction, Teyla and Keller mourn his loss as a remarkable man. (SGA: "The Seer")
Weeks after Davos' death, his vision of the destruction of Atlantis is revealed to be of the destruction of the Asuran copy of Atlantis belonging to Niam's faction, proving Davos' words about the interpretation of his vision possibly being off to be right. (SGA: "This Mortal Coil")
- Precognition: Davos' primary ability, he is able to see glimpses of the future which always come true. Davos appears to possess a level of control over this power, targeting his visions in an attempt to find out things such as the fate of the Athosians.
- Vision Sharing: Davos possesses the ability to share his visions with others by taking their hand and concentrating.
- Empathy: Davos was able to sense Doctor Rodney McKay was skeptical of his abilities. He later sensed that Teyla Emmagan wished to ask him something.
- Super Senses: Davos was able to sense that Teyla was pregnant despite her having not told anyone else.