Dark Gift of Norganas, the Finger of Oblivion

Norganas's gift is the power to turn life into undeath. This dark gift allows its beneficiary to cast the Finger of Death spell as an action. After it has been used three times, the dark gift vanishes. When it vanishes, the beneficiary must succeed on a DC 15 Constitution saving throw or drop to 0 hit points. This dark gift turns the beneficiary's blood pitch black and viscid, like tar.