Luciela

Luciela was Claymore #1 during the same generation her sister, Rafaela, was #2. She later awakened and became known as the Abyssal One of the South before becoming merged with her sister.

Appearance
Luciela has the appearance of a young girl, presumably the appearance she had when she awoken. She has long hair which she wears in bunches, much like Dietrich's. She wears a long dress with lots of ruffles in her first appearance in the manga.

In her awakened state, she is a large humanoid with feline hindlegs. Her head resembles that of a cat and has two gaping jaws, one atop the other. In battle, Luciela uses her foreclaws and the two long, muscular tails extending from her hindquarters. Her tails sport multiple fanged mouths along their length, and Luciela can manifest similar mouths anywhere upon her person.

As a Claymore
Luciela became a Claymore at the same time as her sister Rafaela. This was a time when Teresa was still a child. The Organization used her and her sister in a "Soul Link" experiment. The experiment failed when Rafaela was unable to pull her sister back form her awakened state, causing Luciela to completely awaken. Her awakening was disastrous and drove the Organization to the brink of ruin, as it took place in the Organization's headquarters. Alicia and Beth are a successful product of this technique; it was said that the project only worked with identical twins, which Luciela and Rafaela were not. She left the headquarters and eventually became the Abyssal one of the South.

Fight with Isley
She lived in the Southern Territory, presumably alone, until Isley of the North came to invade her territory. Luciela and Isley began to duel over Luciela's territory, which ultimately led to her defeat. She retreated after losing all of her Yoki. Injured, she reverted back to human form and eventually came across Rafaela. Wanting to finish off Isley, she embraced her sister, and pleaded for her to Awaken and align with her. But Rafaela broke her weakened sister's back, apparently killing the latter.

After Seven Years
Luciela and Rafaela's bodies are in the possession of Riful, who is wishing to awaken them into a much more powerful being. However, she isn't able to do so on her own, and ultimately captures and enlists the help of the Claymore Renee. Renee is able to stir the merged being, but it is ultimately Clare's presence that awakens the merged sisters.

This newly awakened form looks extremely similar to Clare and Teresa the twin goddesses of love.