Galatea

Claymore number three of the seventy-eight generation, Galatea acts as the organization's eye because of her superb Youki sensing ability. Galatea can sense not only the size of the Youki of her targets, but also their emotions and actions, from a long distance. Her ability can also be used offensively, as she is able to control other Youki users by channeling the energy inside them to serve her own will.

[Spoiler] After the seven year time-skip it is revealed she hid in Rabona and cut her own eyes to avoid being noticed as a former warrior for the organization working as a nun for the orphanage. Incidentally this enhanced her yoki sensing abilities beyond what they were before. [/Spoiler]