At some point during their time together during training, Geralt and Gweld practised arrow deflection, and agility on the training equipment before being subjected to a witcher trial, which led to Gweld suffering from nightmares later on.
Later, a month before the planned tournament with the School of the Cat, Gweld, Geralt, Gardis and Aubry rode to a nearby inn to exchange words with the other witcher school. Before going in, Geralt and Gweld switched their witcher medallions, as a good omen. The competing schools kept a competitive conversation until Gweld began a sword fight against a Cat School witcher. The group was then ambushed by bandits who helped the Cats to capture the Wolves, who were subsequently saved by Vesemir and Guxart arriving.
Gweld was asked to train with the Cat witchers as they were a member short, and the Wolf School wanted information. He shined in training and was highly regarded by Master Guxart.
A week later, he participated in the tournament against the Wolves, and was put up in a fight against Geralt. During the fight, they both grew suspicious of the Cats, which led to Astrogarus magically forcing him into a lunge attack on Geralt, and in self defence, Geralt was forced to kill him with a sword through the chest.