The youngest among the witchers of Kaer Morhen, and perhaps the last ever trained within its walls, by the start of our tale Lambert had proven his chops many times over, having hunted down many a mighty beast and traversed nearly all the Continents realms several times
Yet he had also developed a reputation for arrogance and sardonic humor, and his gruff and at times excessively blunt manner could irritate even his fellow witchers of the School of the Wolf. Whatever his vices, it went without saying that Lambert would brave the fires of any hell for his companions.
If destiny truly chooses which boys become witchers, then in Lambert's case it had made a twisted, cruel choice. After hearing his story, Geralt had to admit that Lambert had every reason to be unenthused about the lot fate had granted him.
Though Lambert made no secret of his hatred for Kaer Morhen, when the time came to stand in its defense, he did so without a second thought.
During this battle he came within a hairs breadth of losing his life. Luckily, Geralt arrived in the nick of time and together they held back his attackers.