That was a question Korra had been answering for close to a year, and she knew it was coming. "On my world the Avatar is the only person who can bend all four elements." She opened one hand to produce a small flame and swept other about her, drawing what little moisture she could from the air until a small blob of water was in her other palm. "Earth, Fire, Air, and Water. It’s the Avatar’s job to keep balance in the world, and they’re also the bridge to the Spirit World. Visiting it can be kind of crazy from what I’ve seen."