Prophecy, perhaps?

It waits in silence,

Cloaked in shadows.

It watches the world in hate,

Longing for sweet revenge.

It was exiled,

Banished by the angels.

Rightly so,

For it was evil.

It loves to cause fear,

Feeds on pain.

It bathes in blood,

Plotting the world's demise.

If not stopped,

The world shall be thrown into darkness.

Although it remains in hiding, 

It will reveal itself in time.

***** 

Perhaps another prophecy? Either of another evil or the same one that lurks beneath the waters.