Bertolt was a quiet young man who identified himself as someone with a weak will that follows popular opinion. Likewise, his instructor noted him to be a person with great potential, but an utter lack of initiative, however when put in a confident or enraged state, He can become detached, indifferent and cold, allowing him to fulfill his savage duty more efficiently. However he tends to be quiet and self reserved, and is stronger than he looks on the outside, and is a shy well mannered young man