Zeldris of the demon race following the events of the 7DS, decides he wants to atone for his sins, and is sent forward in time, to 793 of the Fairy Tail universe, our story picks up on July 7th, 793.
Lucy finds Hell Keys and quits Fairy Tail.
Travelling to see the world, the Seven Deadly Sins and their allies stumble upon the Kingdom of Fiore while on a journey away from Britannia in the aftermath of saving the Liones Kingdom and the world from Hendricksen's sinister plot (AU). There they encounter the country's #1 Mage guild called Fairy Tail and joined in their adventures together! Nanatsu no Taizai x Fairy Tail