He strikes as an arrogant young man that doesn´t hold back any words. But he is actually really kind. His serious personality is due to him being raised by the Ozwell family after his father separated him from Asbel. When he was a kid he was forced to follow Asbel into doing things that would eventually make both of them get in trouble, and after an incident where an important person died, they blamed Asbel and thought it would be best for Hubert to be far from him, as Asbel was a bad influence. Ever since then Hubert has looked down on Asbel.
Source from Wikipeida