You had to Time Travel to help the members of Early Emerald Prime Unite to fight against Erza and Satou, then you fought alongside them defeat to help defeat them.

But when you were coming back to the future, you got teleported to Time Nest, when you look at your sides, you see a slightly shorter girl who seems to be very angry at you.

"What you did is a mortal sin, and making Time Machines is a crime! Work under me if you want to be forgiven!" She scoffs you, pushes your ear while you apologize a lot.