Made of Earthsteel, adorned with gemstones that channel power from each of the Zodiac signs, the Eye of Ouranos contains great mystical energies. Created in the First Fires, this amulet allows its bearer to manifest physical traits originating from the stars.
Each constellation was put into the heavens by the gods, and they actually live—each collection of stars is sentient. Gemini IS the combined form of Castor and Polydeuces, the twin sons of Zeus; Sagittarius IS the centaur, Chiron. Leo IS the Nemean lion. They exist. It's the only way that Brandon can draw upon that power.
In addition to that, Ouranos, the son and husband of Gaea, gave one of his eyes to create this amulet, to allow the bearer to—
...well, that will be revealed in the sequel to Task Force: Gaea. The power of a Protogenos, a primordial being, cannot be measured, cannot be understood, except by other primordials. Being the cosmic zookeeper is just one of Brandon's abilities.
More will come, when readers see the story of Memory's Curse unfold.