Kingdom Hearts; The Light's Keeper

Y is a young keyblade wielder in training well on her way to becoming a master one day. But when the day she's waiting for arrives, things begin falling apart. Suddenly strange creatures called Unversed are spreading darkness across the worlds and a strange masked boy is warning about her dying light. She's forced to break a rule she never thought she could. Never leave home.

X is a newly made Heartless. He likes to think he's getting the hang of it. But it's still not what he wants to be. With the promise of returning to normal he's prepared to do anything. Even lie to those who would call him friend. But it's not as easy as it seems, especially when some see right through him.

It was fated long ago. No matter what is done history is bound to repeat itself. Darkness shall prevail and the light expire.