Battler is the son of Rudolf and his first wife Asumu, and is generally considered to be the main protagonist of the series.

He is extremely stubborn, and is afraid of "shaky" transportation, fearing he might fall off a boat. At first glance, he appears to be hotheaded, cocky, and even a little perverted. However, he has a heart of gold he isn't afraid to show when the situation calls for it.