Negativity will get you nowhere

Kali Dragneel, Nastu's sister, and a once light wizard turned dark before rebelling for a reason nobody knew. The only noticeable change was an emblem on the underside of her right forearm and a strange tribal tattoo wrapped around her left bicep. Vanishing without a trace, she resurfaces in a job request from the True Cross Academy to take her down. The flyer itself was strictly for the guild masters' eyes and read;
Please send the strongest wizards available as soon as you can! Please, it's very severe.
Makarov, alarmed by this, sends their strongest team, nervous of what was to come and sending Gildarts, Cana, and Gajeel along as well. Upon arrival, team Fairy Tail finds the group at the T.C.A. and finds out just how serious it is.
*Angel's child* Shortly after, Kali gets called on a job request regarding demons. Interested, Natsu follows, and so does Lucy and Happy. Undercover, she teams up with Yukio Okumura to help protect his brother Rin.