Legend of Korra: One-Armed Wolf

When Korra was found as the new Avatar, The White Lotus was tasked with protecting her. However, they recruited help from an ally, one who provided a person to grow alongside the new Avatar as her protector.

This guardian shinobi is Wolf, a non bender, trained specifically to defend the Avatar until his dying breath.

Disclaimer: I own no characters in this story as they belong to either FromSoftware or Avatar Studios