III has a nice, friendly and gentle demeanor, unlike his brothers' cold and brutal nature. III loves his family a lot and doesn't want them to fight, attempting to mediate disputes between IV and V. Tron stated that III always completed his missions, which are usually important. V trusts III more than he does IV, due to IV's reckless attitude.

Like his brothers, he swears revenge on Dr. Faker, though he cares more about the family's well-being. Though concerned about his family's fate, he also shows concern for his enemies from time to time.

He is later revealed to be the son of Tron (Byron Arclight) and brother of IV and V, with his real name being Michael Arclight.
(Source: Yu-Gi-Oh! Wikia)