The Green Lantern Corps may be one of the DC Universe’s most powerful organizations, but even its own members admit that Sinestro's army may be a bit more powerful. A reflection on the state of willpower and fear makes a strong argument for the power of the Yellow Light.
For eons, the DC Universe has been protected by the forces of the Green Lantern Corps. By harnessing the Green Light of Willpower, the Corps' members can use their Power Rings to manifest constructs of anything they can imagine. As long as they have enough willpower, there's nothing a Green Lantern can't do with their ring. That said, they aren't the only beings in space who know a thing or two about ring-slinging. The once powerful Lantern Sinestro traded in his green ring for a yellow one and opted to use the power of fear when he made a corps of his own.
And by the Green Lanterns' own admission, the Yellow Light Sinestro has harnessed might be even more powerful than will. The debate over the two power sources came up in Green Lantern #22 by Geoff Johns and Ivan Reis. Hal Jordan is fighting off a Parallax-possessed Kyle Rayner on the Sinestro Corps' home base of Qward in the Antimatter universe. Just as all seems lost for Hal, a swath of Jordan's fellow teammates join him in the fight. However, in spite of the assistance, Parallax proves to be too powerful for the team to handle on their own. The Lanterns retreat into a chasm in order to reassess and marvel at the carvings on the walls. The scriptures speak to the power of fear, leading several Lanterns to discuss how pervasive fear is compared to something like willpower.
Sinestro Has An Advantage Over The Green Lanterns
Essentially, because fear is the primary emotion of the Sinestro Corps and fear is one of the most basic of emotions, it’s much easier for the Sinestro Corps to tap into their source of power. While the Green Lanterns are all capable of great will, not every creature in the universe is as capable of overcoming the same emotions as a Lantern (after all, the Green Lantern Corps only selects the few that are able to rise about their own fears). The Green Lanterns may be on the side of good, but Sinestro's Corps is possibly the mightier of the two.
Believing that emotions were too unwieldy, the Guardians of the Universe founded the Green Lantern Corps with the stable Green Light of Will. As the center of the Emotional Spectrum, it’s a solid choice. However, willpower isn’t something that comes by as easily as fear. Fear is one of the most primal and common emotions a sentient being can feel. And unfortunately for the Green Lanterns, there is far more fear in the universe than there is willpower. Considering that the Yellow Lanterns draw their powers from the universe’s collective fear, it stands to reason that the Sinestro Corps is more powerful than the Green Lanterns.