Avatar-The First Avatar-Ying

I took an idea I created ages ago and avatar and put them together. My idea was called The First, the first godly being that ever existed. So on to the story for this character Ying. Korra finds out that there is a great evil coming that she will not be able to defeat without finding out the secret of the first avatar. Long journey, she goes to some ruins, opens the ruins thinking that the secret to save the world is in them but in fact she is wrong. She releases the great evil, the first avatar. Well a part of him. Later when she discovers some other ruins Korra will find the other part of The First Avatar. She had met the evil one that she released and now the good one. At one time the first avatar was a balanced being and the only human who could control energy. He like so many of us fought with his fears, anger and inner demons. But on a larger scale. When his wife passed he lost nearly all control. So he tried to separate his evil energy from his good energy. When he did this the evil energy didn't disappear it actually became its own being. An evil clone of the good First. They fought but were equally matched, in order to save the world the good First locked both of their powers away. Thinking the world safe in his catacomb coma, the energy still continued through the world on a smaller level. Simply becoming the elements and thus creating the avatar we know today. Will Korra be the push that the good First needs to final defeat the bad First, Ying. Or will the world fall into further chaos as Ying the bad first starts to take over and gather an army of all the big baddies your mind couldn't even comprehend. The powers of the First are considered unlimited because no one has learned there limits other than it only being equal to itself.