User blog comment:Miskos3/Fairy Tail 528: Dragon of Magic, Review/@comment-7418318-20170325193741

I wonder if maybe the Eclipse Gate that brought the DS and Dragons to the present could have been active this entire time, but it was so well hidden that nobody ever found it.

But due to Universe One it was brought out of it's hiding place and Ichiya stumbled upon (or rather through) it and that's how and why Anna (if it's really her) got into the present.