User blog comment:FairyRaven/Fairy Tail Chapter 416: Tartarus Arc: Final Part, Review and Commentary/@comment-77.194.131.213-20150119141826/@comment-9595671-20150119204040

Its possible she's asborbed more than her usual Satan Soul, Haplas Soul and Sitri Soul but they're the only 3 souls she actually battles with. So its likely she just took it and won't use it cause she really doesn't have a use for it.