Doesn't exist on Unholy talent spec.
Put a "Blocker" cause it's the core spell for UH playstyle. We can't do anything without Death Runes.
It is not available to Unholy anymore we shouldn't have it. Now festering strike has a passive which makes the runes spent into death runes but anyways it is not working http://www.wowhead.com/spell=85948/festering-strike