Each Green Lantern possesses a power ring that gives the user great control over the physical world as long as the wielder has sufficient willpower and strength to wield it. The ring is one of the most powerful weapons in the universe, and can be very dangerous. While the ring of the Golden Age Green Lantern (Alan Scott) was magically powered, the rings worn by all subsequent Lanterns were technological creations of the Guardians of the Universe, who granted such rings to worthy candidates. These individuals made up the intergalactic police force known as the Green Lantern Corps.

The Blue Lantern Corps Story:
First formed by the banished former-Guardians Ganthet and Sayd, they are based on the planet Odym and their powers are fueled by the emotion hope.

The creation of the Blue Lantern Corps is rooted in the events that transpired during the Sinestro Corps War. During the first half of the War, Ganthet and Sayd serve as a dissenting voice among the Guardians as they acknowledge that the Blackest Night prophecy within the Book of Oa is coming to pass. Their willingness to embrace emotions and the love they have for one another leads to the two being banished from Oa.

After their exile, Ganthet reveals the Blackest Night prophecy and in his description he says: "Elsewhere, a flicker of hope will shine from deep space, like a lighthouse warning the ships away from the rocks. The blue light will hold the line in spirit if not in strength." It's revealed that Ganthet and Sayd have settled on a planet (later named as Odym), and have created a blue power ring with the intent to form their own Corps.

Symbolizes: Hope
The Blue Rays of Hope

The Blue Lantern Corps Oath:
"In fearful day, in raging night,
with strong hearts full, our souls ignite!
When all seems lost in the War of Light,
look to the stars, for hope burns bright!"