Succubus queens

The succubi are ruled by four queens: Lilith, Eisheth, Igret and Naamah. The queens have distinct abilities above that of normal succubi, but one they all share in common the ability to make use of both lust energy and chaos energy.

Euryale's Gambit
In Euryale's Gambit, we learn from Igret during the Townsville Cathedral Ambush that the four succubus queens erased Euryale's memory upon her request. After they performed the ritual, they betrayed Euryale by convincing her that she was a succubus. They taught her how to make use of lust energy and to serve the interests of the succubi. The queens believed the that although Euryale appeared broken, she could be made into a powerful servant they could use in wars between races.

However, even though Euryale had her memory erased, remnants of her former personality constantly surfaced as she kept acting out when she encountered scenes that reminded her of her sister, in particular the abuse of women. To fix this, the succubus queens placed upon her the curse of apathy. This curse was effective for hundreds of years but was partially broken when Euryale absorbed the lust energy from The Entity during the events of Catching Heat.