The Stiletto's Thirst  

required!

1. Kill 10 Adherant Vampires. These can be found along the left wall after zoning in and going through the water. Just keep left, and once you are back on dry ground you will start to see them.
2. Examine the stiletto for the next step.
3. Kill Hellhounds until you receive a fiery heart. This a random auto-update drop. On average it will take about an hour to get the update.
4. Examine the stiletto once again.
5. 
   a dark altar.
   You will need to find a dark altar and perform a ritual sacrifice using the stiletto and fiery heart. The altar can be located at -109, 27, -7 Copy . The altar looks like a light post. This is up the ramp, across both stone spans, and just to the left. Right click it to get the update.
6. Next you will have to kill 50 vampires in The Crypt of T'Haen. Any vampire will count towards the quest.

After the 50th kill, you will receive your reward.