About:
  Serana Volkihar was raised in a Molag Bal-worshipping cult many millennia ago and became a pure-blooded vampire through a ritual along with her mother, Valerica. As a pure blood, her blood magic (sanguimancy) is more powerful than lesser vampires.
 

Skills:
Hand-to-Hand - Adept
Archery - Apprentice
Swordsmanship - Apprentice
Stealth - Apprentice
 

Magic
Sanguimancy - Master
Necromancy - Expert
Cryomancy - Expert
Soulmancy - Apprentice

Affinities
Weaknesses- Fire and Silver (vampirism)
Resistances - Frost (vampirism) Blood Magic (pureblood)

Relationships:
  Harkon: Before his obsession with The Tyranny of The Sun prophecy, Serana remembers having a loving relationship with her once warlord/king father.

  Valerica: Serana's relationship with her mother was superior to any other; their bond formed by shared isolation and love of necromancy. 

  ???: Serana thought she was only attracted to men, until a stranger came along... only to vanish.

About:
  After retrieving one of the elder scrolls for Lord Harkon, Serana was sealed away, lying dormant for centuries until The Dawnguard discovered her. Serana has conflicting feelings about the prophecy. 
 

Skills:

(same as before)
Hand-to-Hand - Adept
Archery - Apprentice

Swordsmanship - Apprentice
Stealth - Apprentice
Survivalism - Apprentice

Magic
All - Serana awoke with her magic greatly weakened, although she returned to normal shortly after.

Affinities
Weaknesses- Fire and Silver (vampirism)
Resistances - Frost (vampirism) Blood Magic (pureblood)

Relationships:
  Anya: Serana thinks Anya is rare display of natural beautiful. They are starting to like each other more and more, although Anya is hesitant. She could be a powerful ally if turned into a vampire...

  Harkon: Despite his cruelty, Lord Harkon is still family to Serana. She is looking forward to seeing him again.

  Agmaer: The only Dawnguard member (besides Anya) that Serana doesn't hate. 

About:
  In Season 2, Serana returns home to find Castle Volkihar has fallen from its former glory. More than anything, she just wants answers. (Skills, Magic and Affinities unchanged from Backstory)

Relationships:
  Anya: Serana has taken Anya under her wing and converted her to vampirism. They clearly have feelings for each other, but Serana does not want to grow too close.

  Harkon: Although he's Serana's father, she feels distant from him. Serana believes Lord Harkon's obsession with the elder scrolls will bring only war and destruction to Skyrim. 

  Faye: Serana may be more powerful than Faye but she still feels intimidated by her up-and-coming status in The Court of Harkon. She is also jealous of her relationship with Anya.

  Valerica: After her visit to the Soul Cairn, Serana felt nothing but dissonance with her controlling mother.
 

About:
  Serana has fully defected from the Volkihar Clan in order to help The Dawnguard. 
(Skills, Magic and Affinities unchanged from Season 2)

Relationships:
  Anya: She would do anything to protect Anya. For the first time Serana feels that she has an equal partner that cares for her well-being.

  Isran: Just like all vampire hunters, Isran despises vampires. Yet Serana knows why he's different from the rest... Why he gave her a chance. For that, he has gained her respect.