Since Carrie got much less attention than Reinhardt, Henry or Cornel many fans do not know much about her past. Well here's the skinny.
Carrie spent her young life with a group of wandering Jypsies the Fernandez clan whom are believed to be decendants of Sypha the sorceress from Castlevania 3 and Trevor Belmont the son of Sonia Belmont which would explain why she has so much power.
The Fernandez clan upon arriving in Wallechia was not well recieved and those who were not hunted down as witches by the townspeaple were exterminated by Dracula's minions as he greatly feared their power.
However a wealthy woman by the name of Eastfield took pity on the young Carrie and adopted her. Giving Carrie the identity of her own child Ms. Eastfield provided a good home and a good education for the young Carrie Fernandez.
Unfortunately Carrie's peaceful life would be shattered again by Dracula's forces. Dracula's minions sent waves of forces into the nearby villaiges Searching for one certain child. Ms. Eastfield gave her own life holding off Dracula's minions to protect Carrie from being captured.
Having escaped and being stricken with grief Carrie spent two more years on the run. The tragedies of her life made her cold to the world and to God. Setting aside her fears Carrie swore vengence on Dracula. She would eventually meet up with Henry and Reinhardt who were preparing to attack the castle themselves.
Having Joined forces with the two agents of the church Carrie boarded their ship and set sail across the ancient lake of poison to Dracula's Castle.
At the castle Carrie traveled a simillar path as Reinhardt and eventually met with Malus one of the children whom had been captured by Dracula's forces. Malus seemed to have taking a liking to her. Deeper in the castle Carrie encountered Malus again acting much differently than before. Later she encountered a witch whom had taken an interest in her named Actrise. Actrise attempted to persued Carrie to join Dracula. Carrie having flat out refused the offer was introduced to a lost member of her own clan. Unlike the other fernandez warriors who set off the challenge Dracula this one had been made into a vampire. Carrie was forced to fight and kill her own cousin in a battle of magic power.
Having triumphed Carrie promised her cousin that her soul woud be set free and she would join Carrie's mother in heaven once Dracula was defeated.
Nearing Dracula's hideaway Carrie faced Actrise again. Once more she refused to join forces with Dracula and in a lengthy battle of sorceresses Carrie triumphed proving she had the power to take Dracula down.
It's assumed that in the end Carrie again met up with Reinhardt and fought alongside him to defeat Dracula.
In the bad ending a vampire posing as Dracula is defeated and Malus returns to the town with Carrie and forms a "binding contract" with Carrie to marry her later in life.
IN the real ending Malus is revealed to be Dracula himself in a new and more powerful body. Carrie after defeating the adult Malus finds him collapsed as a child again. In one last ruse Malus tries to take Carrie's hand only to be doused with holy water by Charlie Vincent a powerful Vampire hunter whom Carrie had encountered before (and objected to the way he treated her like a child as we all know Carrie hates that)
His ruse spoiled Dracula revealed his true form a great Dragon like beast. Pulling Carrie and Reinhardt into an alternate reality he fought them with his full power. After a long hard battle Dracula was vanquished and sucked into the pits of Hell.
Carrie and Reinhardt were transported outside the castle and watched from afar as it sank into the lake of poison.
Having Parted ways with Reinhardt Shneider Carrie visited the grave of her mother (the adopted mother). Leaving a bouquet of flowers she was finally able to accept the hand fate delt her and move on with life.So that's Carrie's life in a nutshell.