Gaston had neat black hair tied in a ponytail and a gentle, though worn, face.
Three years after Guts joined the group, Gaston was one of the raiders who was shown to have a deep respect for Guts, both as a commanding officer and friend.
Gaston never regretted joining the Band of the Falcon, but, as Guts revealed in a discussion with Casca, wanted to save up his earnings to open a clothing shop in Wyndham. He was unable to achieve this, likely because he was outlawed like the other members of the band, but upon revealing this to his former commander, showed no sign of disappointment, instead joyful in the fact that his place was with the band and that the raiders were a family to him.
It is hard to say what the extent of Gaston's abilities may have been, as he was never really seen in action. However, being ranked second in command of Guts' Raiders, it can be assumed that he was at least a very competent warrior and strategist.