Guowei

Guowei (グオウェイ, Guouei) was the Crown Prince of Ba Sing Se, following tradition where the oldest child would become the successor to the current ruler, but due to his inefficiency to properly Earthbend, preferring to follow a more Airbender-like style, let alone being inadequate in political matters, the 43rd Earth King decided that his other son would take the mantle after his passing. Due to the events leading up to this, the 43rd Earth King banished his reject child from the entirety of the Earth Kingdom, making him a kill-on-sight target to Earth Kingdom officials, while professing to the people of the Earth Kingdom that Guowei fell to an uncurable illness, holding a funeral for his "dead child".

After being banished from the Earth Kingdom, Guowei roamed around, searching for an Air Temple so that he could assimilate himself into Air Nomad culture. During his travels, he passed out, and was rescued by an Air Nomad, whom of which later became his wife. Finally finding happiness, Guowei lived with the Air Nomads for years, up until a group of Water Tribesmen attacked a sacred location of the Air Nomads in an attempt of freeing the Spirits they've "trapped". This event is what lead to the Spirit Liberation War between the Water Tribe and the Air Nomads. During this conflict, Guowei lost his wife to a Water Tribesman, shortly after she had given birth to their child, who was later found out to be the successor to the previous Avatar. Escaping away from the conflict, Guowei became bitter and secluded, raising his son by himself. During this time, Guowei studied the movement of Waterbenders, in a petty attempt in using the very same style that took the life of his wife to end their lives. This study lead to the creation of, where Guowei began to incorporate it into his fighting style and beginning his life as a blacksmith.

Trivia

 * Guowei's name comes from the Chinese name with the same name, where his name translates to "may the country be preserved".
 * Guowei uses the design of male Musashi from the series Fate.