The DCEU’s first Green Lantern appears in Zack Snyder’s Justice League, and the film's reimagining of the classic character also means a change to Alan Scott, the first superhero to use the Green Lantern moniker. Alan Scott is a Golden Age DC superhero who is not a traditional member of the Green Lantern Corps, having received a modified version of an Oan green power ring that once belonged to Yalan Gur, the Green Lantern of Earth’s sector. Gur only appears briefly in Justice League, but his existence in the DCEU implies that Alan Scott does as well, and Gur’s reimagining means that Scott’s origin would have to be changed as well.
In the mainstream DC Comics universes, Yalan Gur was a legendary Green Lantern who protected Sector 2814, which includes Earth. Unlike most Green Lantern Corps members, Gur’s ring lacked a weakness to yellow objects, but the Guardians of the Universe imbued it with a new weakness: wood. Gur became a tyrant on Earth, and the wood weakness conveniently allowed humanity to repel him from Earth through simple weaponry. Upon fleeing, Gur collided with the mystical Starheart, killing Gur and sending his Green Lantern ring back to Earth, now a combination of the Guardians’ advanced technology and the Starheart’s magic. Alan Scott eventually discovered the ring and used it to help others as the first human Green Lantern, despite his lack of affiliation with the Corps.
Zack Snyder's Justice League flashback shows the forces of Earth, including Yalan Gur, uniting against Darkseid and his Apokoliptian invaders. Although Gur has only a few moments of screen time and no dialogue, he’s depicted as a noble and heroic character who dies fighting Darkseid himself, sending his ring flying into space in search of a worthy new wielder, as per its programming. With Zack Snyder's movie interpretation of Yalan Gur being a traditional and altruistic Green Lantern rather than a tyrant, and with his ring seemingly being an ordinary Oan power ring, the DCEU would need to change its version of Alan Scott if he appears in the DCEU.
The DCEU takes its comic source material seriously, providing authentic representations of DC’s superheroes, and Alan Scott’s differences from modern Green Lanterns are a key element of his character. Scott precedes the creation of the Green Lantern Corps and the Guardians of Oa, with these more famous elements being introduced in the Silver Age of comics via Hal Jordan’s Earth-One Green Lantern comics. The DCEU nearly included John Stewart and Hal Jordan, according to Zack Snyder’s plans for Justice League, but the specific use of Yalan Gur in the Justice League flashback creates a connection to the original Green Lantern title-holder.
One way that the DCEU can still have a traditional Alan Scott origin without Yalan Gur being a tyrant is by having Gur’s ring collide with the Starheart as it searches for a new wearer. Yalan Gur would have died as a hero and conventional Green Lantern corpsman, but his ring would be sent back to Earth, now combined with the Starheart’s magic and thought lost by the Guardians. This would allow Alan Scott to find it and become an atypical Green Lantern as he did in the comics while having a more heroic version of Yalan Gur be part of his backstory.
Alan Scott, like other famous Golden Age DC heroes, was part of the Justice Society of America, a precursor to the more familiar Justice League. The Justice Society will appear in the DCEU via Black Adam, and while its lineup won’t include Alan Scott, its existence provides yet another opening for him to appear in the franchise. Zack Snyder’s Justice League set up Alan Scott with its new version of Yalan Gur, and the Golden Age Green Lantern has an opening to join the DCEU with a slightly different origin.
Zack Snyder's Justice League has a flashback sequence with Yalan Gur, a Green Lantern whose reimagining would affect a DCEU version of Alan Scott.David Miller