Seven Ghosts

The Seven Ghosts are the survivors of the Northern Campaign, who deserted the Organization and hid in the mountains of Alphonse for seven years. During this time, they replaced their worn out Organization uniforms for outfits made out of a sleek, leather-like material that looks very similar to Irene's outfit when she was in hiding.

History
During the seven years in which they hid in the mountains, they trained tirelessly to improve their skills. After the seven years, it is shown that all seven claymores have not only greatly improved in strength and speed, they have also perfected unique, individual skills, such as Helen's mastery of Jean's (the former No. 9) Drill Sword or Clare's mastery of Flora's (the former No. 8) Windcutter. Miria is shown to have perfected a new and improved Phantom Mirage, Cynthia has acquired the unique ability to heal using yoki, Yuma has gained the ability to use her sword as a projectile, Deneve has learnt to use the former No. 11's (Undine) iconic Twin Sword skill, and Tabitha has dramatically improved her ability to sense Yoki. As stated by Miria in chapter 123 of the manga, most of the Ghosts have skill and power equal to that of single digits. As a result of their harsh training and newfound abilities, most of the Ghosts are able to dispatch of awakened beings on their own and easily defeat much higher ranking Claymores of the current generation. A great example of this is when Yuma (Claymore No. 40 of the previous generation) is able to effortlessly defeat the current No. 14.

Shortly after they left the Northern Lands, an Awakened Being Hunting Party gossips about Nina's team miraculously surviving in Alphonse, despite being completely defeated. Rachel jokingly suggests Nina's team were rescued by "ghosts of the warriors from seven years ago." Audrey ironically echoes this comment. The Seven Ghosts are members of the Paburo Hunting Party (Miria, Deneve, Helen, Clare), plus Cynthia, Tabitha and Yuma. It represents Clare's second major group bonding.