What purpose could there be to a vampire's existence if not to gorge upon mortal blood?

Not just mortal blood, but the special sweetness of his own kind settled on his taste buds.

Let me begone, this place burns my spirit, and in it there is a stench of mortal blood.

I cannot call off the old ones who demand revenge and sacrifice in mortal blood!

And I don't want grandchildren with mortal blood.

She touched his temple and her fingers came away sticky with fresh mortal blood.

That explained Gilfaethwy's desire for mortal blood in a most innocent manner.

I had by then drunk my first draught of mortal blood.

She had lost the taste for mortal blood long ago.

That my mortal blood would take their immortality.