An experimental project led by the Mages and Engineers of Auru, as a means to escape their old world in the face of imminent destruction. When that day came, however, the Obelisk project was yet unfinished and untested... leaving the Aurulians with no choice but to activate the experimental artifact. It worked, but at a cost.
Arrival on Atlas
In the broadest sense of its purpose - a gateway between worlds - the Obelisk worked. Upon its activation, the entire city of Auru was ripped from its dying world in the nick of time. Unfortunately, the untested force of the teleportation nearly destroyed the city, as it was dashed upon the rocks of Atlas on an island somewhere in the seas far south of Athera. The Obelisk itself was also damaged beyond repair.
The physical destruction of Auru was not the only side-effect of the Obelisk's teleportation. Soon after their arrival on Atlas, the Aurulians began to notice a varying array of physical and mental alterations amongst those who had survived the Arrival. Loss of memory, physical ailments, and bouts of insanity were among the more common symptoms, though many experienced unique or even delayed effects. Others seem to have been unaffected, however some believe their "Spire Sickness" is simply laying dormant.
Gateway of Worlds
When the Obelisk was damaged during the Arrival, it did not break. Instead, the artifact became warped and entwined with the magical energies of the Spire below it, twisting its unpredictable magic into something the Aurulians never expected. The device began acting like a beacon, drawing refugees of other doomed, broken worlds through the rift and bringing them to Atlas. The Obelisk's reach is yet unknown; on rare occasion, it has even been known to reach beyond the land of the living, bringing the once-deceased back through its rift.
The Great Naurulian Bargaining Chip
After leaving the ruins of Old Auru and establishing their new city of Nauru to the north, the Naurulians began interacting with the native Atherans. Fresh out of the Cirilian War for Independence (and the Great Trade War before that), the worldwide peace accords in place on Atlas seemed shaky at best. Fearing that their people might be conquered or enslaved in the wake of this world's bloodthirst (most of all by the imperialistic Vantians,) the Naurulians bartered for an entirely neutral position on the world stage using the only asset to their name... the Obelisk.
In a world whose population had been ravaged by recent wars, the Obelisk provided a new generation of people to strike out to the ends of Atlas and rebuild it to its former glory. On rare occasion, it provided the resurrection of a loved one. And with the true location of the Obelisk a secret known only to the Naurulians, it provided what many began to refer to as The Great Naurulian Bargaining Chip. To this day, the Mages of Nauru keep the southern island of Old Auru shrouded in magic, masking its location to outsiders, and heralding new refugees of the Obelisk to the city of Nauru.