All the demon blood spilled during the war caused the land to become cursed and the sky lost its light.

"You must have a bit of demon blood in you."

And his demon blood it is which has made you an immortal.

During the sleep, the demon blood mixes with the human's.

This process can be slowed by consuming large quantities of demon blood.

Don't they know that I faced death rather than take the demon blood?

It's too soon, and the demon blood is still churning in you.

And besides that, he has a bit of demon blood, does he not?

My kisses broke her lips a little and I tasted the demon blood.

They then learn through the angel that Jace has demon blood.