Amuda

was once a member of the Lightning Group.

Background
Amuda was once a member of the Lightning Group, whose members were all kekkei genkai users that had been persecuted because of their abilities. They would travel around stealing from criminals and giving their plunder to the downtrodden, intending to do for others what was never down for them. Their group eventually earned the attention of Kirigakure, who tricked them into attacking some government officials of a foreign country. Kiri defended the officials from the Lightning Group and killed most of its members; Amuda, Nowaki, and Karyū were among the few to escape. Such injustice caused Amuda to lose his will to live.

Sasuke Shinden: Book of Sunrise
Chino enlists the help of Nowaki and Amuda to help her take revenge against the hidden villages for how they've treated people with kekkei genkai. Amuda sees this as an opportunity to give his life getting some payback against the villages and volunteers to be converted into a human bomb by Chino. Amuda is embedded into a group of Konoha, Kumo, and Kiri-nin under the control of Chino's genjutsu and sent to attack Konoha; only Amuda is allowed to be in control of his own actions. He is captured and knocked unconscious before he has a chance to detonate. Konoha eventually discovers that he was not being controlled and has his mind read, allowing them to gather information that eventually leads to the capture of Chino and Nowaki.

Amuda, Chino, and Nowaki are given an offer by the Sixth Hokage on behalf of the Fifth Mizukage: use their abilities to help Kirigakure to rid the world of the same evil and persecution they have been subjected to their whole lives, a repentance for those who died in their attacks. The three of them agree.