Legend of Korra x Avatar the Last Airbender Korra
Summary: Korra has not spoken in weeks. Drawn by a silent invitation from Katara, she returns to a sacred spring once used by Kyoshi and Kuruk to cleanse what the world could not heal. And Toph is not far behind. But the surprises do not end there.
Right now, this is just a one-shot. There could be a prologue to this. If the idea was good enough!