Lehai

Lehai joined the Dawnguard after being the sole survivor of a vampire attack on her caravan. One of her friends was turned, but the rest were killed.

She's lithe, pretty, and trained as a merchant, so people underestimated what she could do. She had the natural born ability to be stealthy and she trained up to become an archer. 

Profession: Dawnguard vampire hunter
Skills: Archery, crossbow, sneak.