Its the sun. Simply. The one who raises the sun is currently unknown, or if there is even "one".

Legend about the SunEdit

Legend has it that Night and day will come together.

And then BOOM!

It prohecied Nightwing.

But no one knew what powers he had.

So now as we see.

There is always a creature who flies over the sun and raises it.
The beast that raises the sun.

The Creature that raises the sun.