User blog comment:Jho5689/Fairy Tail 337 and onwards/@comment-1359322-20130624070938/@comment-7418318-20130625131130

Why the princess (or whoever else) opened the gate is no mystery.

Originally the gate was build to go back in time and kill Zeref before he got too powerful. F-Rogue only made them change that plan to the Phase 2 (cannon).

And those unresolved matters are one thing I didn't like about RAVE. They never explained what Plue was or where he came from, how he met with Reshia, how Reshia got her powers, how the time guardians came to be, whether Shuda and Haru's sister really married,...