King Bumi

King Bumi is one of the many important characters in ''Avatar: The Last Airbender. ''He is lifelong childhood friend of Aang shortly before Fire Lord Sozin started the war and in later years he became the king of his hometown called Omashu. In the Water Tribe saga, not long after Aang was released from the iceberg by Katara and Sokka, they visit Omashu (though Aang was unaware that Bumi was still alive at first) and unintentionally cause trouble there which led to one of the Earth Kingdom guards to take Aang and his friends straight to King Bumi. Bumi (now old aged) was suprised that Aang was still a kid upon first glance at him when his guards brought them in for sentencing. Rather than punishing them he threw them "a feast" and had a conversation, Aang lies about his real idenity but King Bumi figures out he's the avatar and forces him to stay in his castle to do three deadly challenges and keeping Katara and Sokka hostage by trapping them in a rock called jennamite. After completion of the challenges, Aang reconized Bumi after Aang figures out his name and hugged out each other.

In the Earth Kingdom saga, Aang and his friends returned to Omashu so Aang can learn earthbending from King Bumi. Unfortunately, it was attacked and held captive by the Fire Nation. Bumi himself was captured and was unable to leave after a conflict with Fire Lord Ozai's daughter Princess Azula and told Aang to find another earthbending teacher that waits and listens before attacking (forshadowing Toph).

Bumi is also revealed to be part of a secret society called the Order of the White Lotus when Team Avatar (minus Aang and Momo) was looking for Iroh. Like many of the original Avatar characters, King Bumi died of natural causes long before The Legend of Korra.

Abilites
Bumi was a powerful earthbender that is said to rival that of Toph. Even at old age, he's still a powerful earthbender  and is very agile in combat. He can hold his own against several people even Aang when they first reunited in the episode The King of Omashu. When restrained and/or kept away from earth he can still earthbend by levitating rocks from the ground at mid air as seen in the episode Sozin's Comet part 2: The Old Masters during the The Day of Black Sun to break free from his prison. He also proves to be a dangerous force to be reckoned with as he is able to hold his ground against several people while freeing his city against several fire nation armies and fighting many fire nation mecha tanks. Bumi may have seismic sense like Toph as he earth-bent fire nation soldiers completely without looking.