Ryler Dorant, also known as Needles, was a male Human doctor who was a lieutenant in Havoc Squad, an elite team of Republic troopers serving in the military of the Galactic Republic. He, along with most of Havoc Squad, joined the reconstituted Sith Empire during the Cold War between the Empire and the Republic.
In 3643 BBY, Ryler served as Havoc Squad's medic, in which he was primarily focused into synthesizing combat stimulants. He was stationed on the planet Ord Mantell during the Separatist War, part of the larger Cold War that began when the returned Sith Empire ended their invasion. During the Separatist War, he and the rest of Havoc Squad defected to the Sith Empire, with the exception of one member.
Needles eventually traveled to Taris and weaponized the rakghoul plague. With the intention of making it fast acting, he tested it on newly defected Republic troops and captives brought to him by the Death's Claw pirates of Fallenspire Stronghold. The new Havoc Squad, led by the original member who did not defect, managed to stop and kill Needles, ending his experiments. His position in Havoc Squad was later filled by Elara Dorne.
Dorant's laboratory was later sought out by the rogue Jedi Ki Sazen, who sought his research on the rakghoul virus as part of her plot to create a rakghoul army with Doctor Nasan Godera's Ultrawave Transmitter and take control of the planet.
- Star Wars: The Old Republic Encyclopedia