This story is a sequel to The Teacher, the Sorceress, and the Wonderbolt
Far in Equestria's past, an old threat once more rears it's head, seeking revenge on the princess who thwarted it; a princess that is no more, her life claimed in the effort to destroy it. But this time is different. This time, it's come prepared. This time, it won't underestimate its enemies. This time... it can't lose.
Just an FYI, even though it says this is a sequel to TSW, it is in fact, a prequel to it. Sorry for any confusion.