Zeref meets the Trix

After the war between Fairy Tail and Zeref and his army, Zeref lost. However, in order to keep an eye on the immortal, he was allowed to join Fairy Tail as long as his brother kept an eye on him and promised to take him down if needed. There was another agreement that he no longer attacks earthland. It had been several years since the war ended at the point our story first begins. Earthland had been discovered by the magical dimension, and word quickly spread throughout the magical dimension of the wizard guild with so much power that not even would-be conquerors dared to try and conquerors that planet. New technology soon arrived on earthland and soon the guilds of the various parts of the planet was able to become intergalactic.

This is the time where the Trix comes into play. They were still trying to become empresses of the universe, however they have continually been thwarted by the Winx Club. They soon got wind of the wizarding guilds and decided not to attack the Winx Club by themselves, but instead to attack them using the power of a wizard backing them up. They felt a little nervous about what they were about to do, but knew that it was the only way.