A cool plot could involve a mission where the Young Justice team and a group of Green Lanterns have to team up. There could be some initial friction between the two groups due to different methods and ideologies. But as the story progresses, they learn from each other and combine their strengths to defeat a powerful common enemy.
Perhaps a story where a Green Lantern ring chooses an unexpected candidate in the Young Justice universe. This person might not have the typical 'hero' qualities at first. They then have to prove themselves not only to the Green Lantern Corps but also to the Young Justice team while dealing with the newfound power and responsibility.
One plot idea could be the sidekick having to step up when the Green Lantern is incapacitated. They might have to face a new and powerful villain alone, using their own wits and the limited Green Lantern powers they've learned. For example, they could use the power ring to create constructs in creative ways to outsmart the enemy.
A cool plot could be an OC Green Lantern who has the ability to create constructs that can mimic different elements from their home planet. So, if their planet has a lot of crystal formations, they can create crystal - like constructs that are stronger and sharper than the normal green constructs. This OC could be on a quest to find a lost artifact from their planet that has the power to enhance the Green Lantern rings even further.
In 'green lantern rwby fanfiction', a plot could involve a character from RWBY being chosen as a Green Lantern. For example, Weiss. Her strict upbringing and sense of justice could make her an interesting Green Lantern. She would have to learn to control the power of the ring while still dealing with the problems in her own world, like the Grimm. And she might use the ring's power in unique ways, combining her glyphs with the constructs created by the ring.
One idea could be that the Green Lantern Corps discovers a threat that has its origin in the Marvel Universe, like a powerful artifact from Asgard that is being misused. The Green Lanterns then have to team up with the Avengers to retrieve and safeguard it. Another plot could involve a character like Hal Jordan being accidentally transported to the Marvel Universe and having to work with Spider - Man to find his way back home while also facing a common enemy.
One idea could be a crossover where the Young Justice team has to team up with the Justice League to face an interdimensional threat. Maybe a powerful villain from another dimension is trying to invade Earth and the combined skills and powers of both groups are needed to stop it.
Maybe a story where some of the younger members of the Young Justice team are frustrated with the Justice League's methods and decide to take on a mission on their own, but end up getting in over their heads and have to call in the League for help. This could lead to a lot of character development and some interesting dynamics between the two groups.
Hal Jordan could be the main character. He could be in a mentoring role for the Young Justice members, sharing his experiences as a Green Lantern. His cocky and confident personality would add an interesting dynamic to the story as he tries to teach the younger heroes.
A good plot idea might involve Artemis getting kidnapped. Green Arrow then has to track her down, using all his skills and resources. Along the way, he discovers some secrets about Artemis' past that she has been hiding from him. Or perhaps a plot where they are both framed for a crime they didn't commit. They have to work together to clear their names, while also dealing with other superheroes who think they are guilty.
One idea could be that the Young Justice team gets accidentally transported to an alternate dimension where the Justice League has turned evil. The Young Justice members then have to figure out how to reverse the situation while also evading capture from their once - heroes. Another could be a time - travel plot where the Young Justice team travels back in time and teams up with the early days of the Justice League to stop a threat that was thought to be long gone but has resurfaced in their own time. A third idea is that a powerful new villain emerges who can only be defeated by a combined effort of the Young Justice and Justice League, but first they have to overcome their differences in fighting styles and leadership.
One idea could be a misunderstanding that leads to a battle. Maybe a villain manipulates the situation so that Young Justice thinks the Justice League has turned evil. For example, the villain uses mind - control technology on some of the League members and Young Justice has to fight to save them.