A long time ago, Lanjyr (that's the name of the continent area not the planet, but let's stick with it) was a lone world among many in the universe. The Ancients (orcs) were the major race. Lanjyr came to the attention of invaders (aliens, devils etc) who used portals to invade. The Ancients came up with a plan; build a new solar system, adding a new plane (planet) that would prevent portal invasion. They would also need to swap in other worlds to provide elemental energies to sustain Lanjyr (fire, earth, time etc). This plan would be accomplished via the Axis Ritual, which would build the new solar system from planes grabbed from across the universe.
The Ancients performed the Axis Ritual. This involved travelling to each plane they needed to make a planar icon, setting them out on a big ritual site in the place now known as Axis Island, and placing a massive golden disc atop the ritual site at the end- the Axis Seal. The Obscurati plan is to open the seal, mess around with the planar icons and thus change what planes are in the solar system and are influencing Lanjyr.
There are a couple of other intricacies- like the fact that the Axis Seal/Ritual also creates the sun- but that's the core of it.