User blog comment:HaLo2FrEeEk/Full Dawnguard playthrough coming Tuesday!/@comment-3252491-20120626202100/@comment-1080767-20120628044836

No. Just one boss fight with Harkon (That's not a spoiler, right? You knew that already, didn't you?  DIDN'T YOU?!). This is because Harkon and his whole family are special vampires.

SPOILER

Harkon, Valerica, and Serana were given their Vampirism through a ritual to Molag Bal, the creator of Vampirism. Thus, they have a more prominent strain of Vampirism that grants them superior abilities. Serana describes the ritual as degrading, and Valerica details how females are used as offerings to Molag Bal, and his selecting of the offerings is considered an honour (to which Serana clearly disagrees). Thus, these females are unique in that they yield what is called the "blood of a daughter of Coldharbour", which is significant in a prophecy that Harkon believes will blot out the Sun. Serana and Valerica both acknowledge that they carry this blood, and the Dragonborn may choose to as well and allow Serana to feed on her (provided that the Dragonborn is female). Well, theoretically, at least. I don't know if it's the same for you to carry their Vampirism when the source is not directly Molag Bal. I wouldn't say that you're a "daughter of Coldharbour", but you certainly have the powers of one and can become a Vampire Lord at will.

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