Fairy Tail: New Generation (Sting X OC)

Taking place one year after the Battle of Tartaros, a new guild, Phoenix Wing emerges from the the no where in the Magic Games in Crocus. The whole guild is 2 non-active magic users, 3 SS-Class wizards, 1 S-Class wizard, and 2 Saint-Class wizards. Things get interesting when it is discovered that the most powerful of the guild, one of the two Saint-Class wizards, Hikaru Kawasaki, is the younger sister of Zancrow, the Flame God Slayer who was killed by Zeref in the Tenroujima Island Arc. She was a former member of Grimoire Heart, but ran away from the guild after 3 years of being a member. Also, she is the Silver God Slayer (like Sting, but a God Slayer) and she is the Eternal Mage of Prophecy, who has the endless magic learning capabilities and limitless magic energy of the ancient goddess Hekate (the goddess of magic), which was passed on through Hikaru's family to ultimately be able to defeat all of the demons that Zeref created. This means she is the only living mage who can defeat Natsu in a fight. She was imprisoned by an ice mage while she was travelling after she ran away. It took her 17 years to finally escape from the Iced Shell that the mage had put her in, so she woke up in the year X791, when the Battle of Tartaros broke out. This is when she began her journey to starting a new guild that would surpass all others.