Water, Earth, Fire, Air.
Long ago, the three books lived in harmony,
Then everything changed when stuffty overused comments attacked.
Only one, the only good comment, could stop him.
But when the world needed him most, he vanished.
Four Years have passed, and the Internet has revealed the new Avatar, a disliker joke named "stuffty".
Although his bending skills are great, he has a lot to learn before she's able to save anyone. But I believe Korra can save youtube from stuffty jokes.