For King, John’s oath represents his distinction from the other Green Lanterns. “John is this utterly unique creation that he chose for himself. So getting his own unique oath seemed to line up very much with the lore and where we’re going from here,” he explained.
What this means for the future of the DCU is still unclear. We know that Aaron Pierre will be back as John Stewart for the Superman sequel Man of Tomorrow, as will Nathan Fillion as Guy Gardner. Whether or not that means that the two GLs will clash or work together while dealing with the threat of Brainiac—or that John will be sent to the off-planet prison of Salvation by Rick Flag and ARGUS—remains to be seen.
However, we can get some sense of future plans by looking at instances in the comics where Lanterns deviated from the Guardians or the rest of the Corps. John himself became a Guardian in his first solo series Green Lantern: Mosaic, in which he was tasked with protecting a planet made up of cities from different worlds. In recent series, especially Geoffrey Thorne’s Green Lantern run and Green Lantern: War Journal by Phillip Kennedy Johnson and Montos, John’s power scaled up even more, so that he could pull off feats far beyond the average GL.
That power upgrade matches what we saw in Lanterns, particularly John’s ability to maintain a bird construct without his ring. However, the real swerve in Lanterns comes from the fact that John’s new lantern has, as King observed, “a bit of yellow and a bit of fear in it.” The yellow impurity and role of fear in Green Lantern lore is complicated, but generally, no one who feels fear will get chosen to be a GL. That changed in the 1994 storyline Emerald Twilight by Ron Marz and Darryl Banks, which saw Hal Jordan turn into the villain Parallax and destroy the Green Lantern Corps. In a desperate move, the one surviving Guardian forged a ring, went to Earth, and gave it to the first person he met: Kyle Rayner.
Throughout the ’90s, Kyle operated as the sole Green Lantern and, as such, acted a lot like John’s promising to act. He didn’t have a Corps, he had no oversight from the Guardians, and mostly stayed on Earth. Moreover, he experienced fear, and was told by several people—including Batman, the Dream Lord Orpheus, and even Hal Jordan himself—that the ability to feel fear would allow him to become the greatest Green Lantern.
Given that Kyle is currently fighting intergalactic restaurant mascots in this month’s issue of Green Lantern, things didn’t exactly pan out that way. Since Hal Jordan and the Corps were resurrected, Kyle’s been a supporting character at best, and he’s completely absent from the DCU. However, it seems like John Stewart will be carrying on that legacy in live action. Or, at the very least, he’ll be remixing it.
