OUAT/VD: Know Thy Enemy (CaptainPierce)

Full summary: Sequel to my OUAT/VD: The Truth Is Out There CaptainPierce fanfic. Instead of it being set in any OUAT seasons, now that the first five curses are broken, there's nothing stopping others from coming to town. Because of this, Kat's enemies find the town and find out that she's alive. When Aurora, Klaus' ex that still wants revenge on Elijah, comes town to take it out on Kat, will she make it out alive? Will she be able to take down Aurora? Can she defeat the enemies from her world?