The Eye is an artifact created by the intelligence of The Harbingers, and the metaphysical powers of Havonian Clerics. The Eye has the ability to warp matter and control teleportation and portals.
When The Harbingers discovered that The Spawn Cores, replicating their portal systems, simply ate or consumed the attacks they threw at them, they created an item that could close portals. They created, The Eye, and many like it. They used them en masse, and when The Cores would consume them, their portals would close, and they would be vulnerable to attack. But then The Spawn began to become more intelligent, more evolved, making their hosts more like slaves, so, to avoid them falling into enemy hands, they destroyed all of these super powerful artifacts but 3, one to a Superuniverse, leaving 5 without them, storing them in the Zenith rooms of the Havens' Apexes. Unfortunately, our Superuniverse happened to have one. Apparently, an Eye can survive its destruction to be repaired by putting its Shards back together, in The Zodiac War there were 13.