Tristan was originally from Piedmont, a "Southie" according to Shade Barrow, and had a drawl. At some point, Tristan joined the Scarlet Guard. He used to practice with his rifle in the gun range at Irabelle and the woods of the Lakelands.
Tristan was part of Farley's team on Operation Red Web, with the goal to infiltrate and introduce the Scarlet Guard into Norta. During that mission, along with his captain Farley, he established contacts within the smuggling operation known as the Mariners and within the Red Army, where he also met Shade.
When the Scarlet Guard's safe house near Corvium was attacked, he fled into the woods with Shade and Farley and separated from them to save Farley. Tristan was missing in action for a while but was one of the few members of the team to survive the raid.
Later, Tristan was one of the Scarlet Guard members that participated in the Sun Shooting at the Parting Ball in the Hall of the Sun, in an attempt to kill four members of the High Houses. Unfortunately, Tristan and the other members involved, Kilorn, Walsh and Farley, were not able to escape as Cal and a group of Sentinels captured them and brought them to the dungeon to torture them for information. Tristan was injured in the attack and got a broken leg, which Kilorn tried to hastily bandage with a scrap of his shirt.
After Farley was tortured by a Sentinel from House Gliacon while Tristan had to watch, Ptolemus Samos stormed into the dungeon looking for his sister, Evangeline. In his anger he used his ability as a magnetron to spear Tristan through the chest with one of the metal bars of the cell, killing him.
Tristan was very loyal and protective of Diana Farley, who described him as the best lieutenant she had ever seen. Tristan was a sniper, very skilled with a rifle, which he always kept close. He had a steady trigger finger and used to make tiny scratches in the metal barrel of his rifle, one for each Silver killed with the weapon. He was also angry, emotional and on edge.
His hatred of Silvers was unable to be hidden. He was proud of Mare for joining the Scarlet Guard after Shade allegedly died. Since he was from Piedmont, the heat did not bother Tristan much.
Tristan was described as being very tall with long, dark red hair. He was also lean and had long legs. No matter how much he ate or trained, Tristan never gained muscle, which was of no consequence, because he was not a brawler. Mare described him as "a beanpole in human form." During warm seasons, freckles appeared and multiplied quickly on his face and arms.
- Tristan and Ann Walsh may have had a close relationship, as moments before Walsh commits suicide, she says, "For Tristan."