In Dawnguard we are introduced to the concept of a "Pure blooded" vampire by the main female protagonist (non player) who spoke of a ritual that had a very high mortality rate. Those who survived the ritual where known as Daughters of Coldharbour, but what was the ritual itself?

Getting violated by Molag Bal?

That was my impression. Yck.

The ritual itself is a vampiric tradition following the manner how Lamae Beolfag became progenitor of the vampire race. She was sixually molested by Molag Bal, and died and rose again as a pureblooded vampire.

Of course, she was an unwilling subject, but females who wish to become pureblooded must summon Molag Bal, who might manifest himself in the form of a man, and then commence with the ritual. Since the females are turned this way by tradition alone, the males are different.

Harkon sacrificed a thousand innocent souls as an offering and tribute to Molag Bal in exchange for eternal life. The price might seem a bit much, but remember that not all women who undergo this ritual survive and are revived as vampires.

That is incredibly...terrifying...

Jesus, at "least" he transforms into a Human...I had the image of people getting torn in half from him. .///.

Maybe its the feminist in me but this method (Harkon) seems like it doesn't really require anything from the aspirant other than a cold heart. Better if Harkon had had to undergo a similar...humbling.