>>17471226I think the portal opened because of the power of the Lake Trio or some shit like that. Which makes me wonder why would that be, and why are the Willpower, the Emotions and the Knowledge related to a parallel universe.
If it's not that, then it may be because of the fact that both Dialga (time) and Palkia (space) were there, openning a portal through time and space to the Distortion World.
Sinnoh's mythology is so fucking cool, dude.