Another plot twist might be that they return as different versions of themselves. For example, they could be from an alternate universe where Voldemort never existed. This would create an interesting dynamic as they adjust to the 'new' world they find themselves in, which is so different from the one they left.
One popular plot twist could be that they return with new magical abilities. Maybe they've gained the power to control time, which would add a whole new layer to the story. They could use this to prevent their own deaths or change other major events in the wizarding world.
A really unexpected plot twist could be that they return but are somehow merged with other characters. Their souls or essences could be combined with some of their friends or enemies, leading to a complex and unique set of personalities and abilities. This would force the other characters to reevaluate their relationships with Lily and James and deal with the new, merged entities.
In some fanfictions, a plot twist could be that Voldemort tries to attack during the wedding. This adds a whole new level of danger and drama to the story. It forces James and Lily to rely on their friends and their own magical abilities to protect everyone at the wedding.
One idea could be that they return with new magical abilities. Maybe James has the power to control time briefly, which he uses to prevent some small tragedies in the wizarding world. Another could be that they return to find that Harry has changed the wizarding world in ways they never expected, and they have to adapt to this new world order.
A possible plot twist is that James and Lily Potter survive but are stripped of their magic. They then have to rely on their wits and the help of non - magical friends to outsmart Voldemort. They could also discover that they have a special connection to an ancient magic that Voldemort is afraid of. This could lead to a whole new battle strategy against the Dark Lord.
The 'love triangle' trope can be popular. Maybe Maddie Potter has a crush on James Potter, but James is in love with Lily Evans. This creates a lot of drama and tension. Another trope could be the 'found family'. Maddie, who may be an orphan or an outsider, finds a family in James and Lily. They take her under their wing and protect her, and she in turn helps them in their adventures.
Another cool plot twist is when they time travel and get stuck in the wrong bodies. James Sirius might end up in the body of someone else in the past, like a Death Eater, and has to figure out how to get back to his own body while also not ruining the timeline. It adds a whole new layer of complexity and humor to the story.
In this type of fanfiction, a plot twist could be that Snape saves them, but they end up having to go into hiding in a completely unexpected place. Maybe they have to live among muggles in a way they never thought possible. Another plot twist could be that Snape saves them, but then realizes that he has put himself in a very dangerous position with Voldemort's followers. So he has to find a way to protect himself while also protecting Lily and James. And there could also be a plot twist where Snape saves them, but they don't believe his motives are pure and they try to escape from him, leading to a whole new set of adventures and challenges.
One possible plotline could be that Lily and James return during the time of Harry's battle with Voldemort. Their return could give Harry new strength and hope. They might use their old magical knowledge and skills to help in the fight. Maybe they could also reunite with their old friends like Sirius and Remus, and together they form a powerful force against the Dark Lord.
Harry would likely be overjoyed at first. After all, he never really got to know his parents. Their return could give him a sense of family and belonging that he's always craved. It could also help him deal with some of his past traumas, having his parents there to support him.
One popular Lily and James Potter fanfiction is 'The Marauders' Era Revisited'. It delves deep into their time at Hogwarts, exploring their relationships with friends and how their love story developed. Another is 'Lily's Choice' which focuses on Lily's perspective during their courtship. And 'James Potter: The Untold Tales' reveals some new and interesting aspects of James' character in relation to his relationship with Lily.
One possible plot could be that James and Lily return to a much - changed wizarding world. They might focus on rebuilding their home and reconnecting with old friends. They could also be involved in mentoring the younger generation, sharing their experiences from the war.