The Lost Guardian (RotG fanfic)

Aeliana "Liana" Wolf is the Lost Guardian of Wisdom and Joy. Killed by wolves, she is a solo Guardian who is the queen of animals. But Liana also knows a certain rebellious winter spirit by the name Jack Frost. When Pitch returns with a new type of fearlings, a fire spirit, and an unnamed King of all the bad guys, love blossoms between the two. Book One in the Lost Guardian series.