Not in Black cry but in the snowy area, once you completed the main quest in Blackry you can proceed to the next area by going another direction that you will have to find a port and ride a boat to the snowy area, once you have found the city in that snowy area you will proceed go to the "Shelter" I don't know what's it called but, you will Meet Ms. Compass again talk to her and donate enough Col to unlock a dialogue that reveals a path for the Succubus named Yseult.