Entralink
The Entralink is a place in central Unova that allows for multiversal travel upon wishing upon the Entree, though it doesn't always work perfectly. It has been used to travel between the Another Universe, AU, PMD-A, PMD-B, the Dream World, and a universe where Tagg ended up taking DS' place as the Platinum "PC", among others.
Getting There
Reaching the Entralink is generally as simple as walking from Nimbasa or Opelucid and crossing one of its bridges, or otherwise simply flying or teleporting there.
Use of the Entree
In order to travel to another universe, or a different realm within the same universe, one must wish upon the Entree (Consiously or not) to do so, which appears to mortal eyes as a twisting, black and white tree. A quirk of travel using the Entree is that the more dissimilar a given universe is to the one the given Entralink happens to be located in, the easier it happens to be to travel to, and the differences must be ones that are perceptible by the user. For instance, PMD-A and PMD-B are amongst the most easy universes to travel, whereas universes more in line with the OU get progressively harder. However, if the universe is one that the user has visited before, then it will always be easy for them to access.
Then Entralink will also always place the user in the Entralink or equivalent of the universe they're visiting, which makes it fairly predictable where they'll end up, a quality not shared by the Griseous Orb, which without the Lustrous Orb to give it precise directional control can place its user in just about any random spot in a given universe.
If the Entree suffers any sort of damage, multiversal travel using it becomes near if not completely impossible until it repairs itself.
Quirks
As it amounts to a multiversal limnal space, objects and even beings from other universes are a decently common sight, particularly when multiversal barriers are weak or otherwise suffering fluctuations. While the bulk are from universes with Pokémon, things from further afield in the multiverse are not unknown. As the Entree Forest to the Entree's north is connected to the Dream World, Dream World Pokémon are a common sight inside it. The area also happens to be an Aura Nexus.
