Piandao

 Piandao is a member of The Flame, who goes by the operative name Sword.

He is the long lost older brother of Ayania and Yasuo, the son of Xian and Fuzen.

Description
His operative name, Sword, aptly describes his abilities; Piandao fights with a Jian blade.

A man with a strict honour code, Piandao firmly stands by his oath to the Flame. He is ruthless to opponents or allies who break their word.

He has been initiated into the Order of the White Lotus, and is ostensibly working within the Order of the Flame to bring the latter back into the fold of the former where it belongs.

Abilities
Sword fights with a Jian blade. He is exceptionally agile and is also fairly strong.

He is capable of taking on multiple opponents at the same time, as well as single combat, despite whether they fight with weaponry or bending.

Backstory
Sword first appeared in Omashu, alongside Shadowflame and Archer. He defended his mentor, even when Shadowflame threatened to kill two young waterbenders, Kaidas and Taidan; even when the latter child was in fact murdered. He crossed blades with Yasuo, who recognised some of the unique sword forms that Sword used.

Sword sought out and attempted to duel Yasuo. When others interfered, he called off the duel, delivering a killing blow to his ally Archer who had attempted to interfere and kill off some of the Lotus Progeny who were watching the duel.

After the death of these two operatives, Sword became second in command of the Flame in the area, with a ship of soldiers under his command. The Flame converted an Earth Kingdom village to the Fire Nation, and they began to mine the coal from the area. Here he encountered the Lotus Progeny twice more, first allowing them to leave, and then arresting them after they brawled in the streets and a citizen of the village was killed.

Aboard the ship where they kept the Lotus Progeny, Sword experienced a shared vision with the captives, where his identity as Piandao, brother of Yasuo and Xian, was made plain. After this, he gave Fi his word that he would be her advocate.

The village of "New Azulon" put the Lotus Progeny on trial. When the magistrate and his Flame advisor Litklo broke their honour and ignored the verdict of the people, Sword took it upon himself to free and fight alongside the Lotus Progeny. Sword killed Litklo, his direct superior, with the words "My name is Piandao."

Since then Sword has ostensibly been working to lead the Flame back to become a part of the White Lotus, as they were always meant to be.

Relationships
Piandao knew his parents only when very young.

He was mentored by his aunt Aoko, and her husband Boran. After Boran's death, he was mentored by his step-uncle Stronti, until he left to join the Flame, under Shadowflame.

Piandao is unsure of the Lotus Progeny, but he seems to desire to know his siblings better. He also clearly respects Fi for her logical thinking and untrusting nature.