A plot twist could be that Lemon is secretly related to one of the main villains in the Legends of Tomorrow universe, and Vixen has to decide whether to trust her or not. This would add a lot of tension to their relationship.
Maybe in the fanfic, it turns out that the power Lemon has been using all along is actually a curse that was placed on her by an ancient enemy. Vixen discovers this and has to find a way to break the curse without killing Lemon. This would involve a lot of research and perhaps some dangerous adventures to find the right solution.
One great fanfic could be where Lemon has some sort of time - traveling adventure with the Legends of Tomorrow crew and meets Vixen. They could team up to fight a common enemy that threatens both their worlds.
A possible plot is that a powerful enemy from the future in the Legends of Tomorrow timeline discovers the power of chakra in the Naruto universe. So, they travel back in time to try and harness it for their own evil purposes. The Naruto characters, along with the Legends of Tomorrow crew, must then join forces to stop this enemy. This would involve the Legends of Tomorrow team learning about ninjutsu and the Naruto characters learning about time - travel technology.
The plot could revolve around Sara's pregnancy being a surprise to everyone, including herself. She then has to figure out how to balance her life as a Legend with the new life growing inside her. Maybe she has to take a step back from some dangerous missions.
One idea could be a crossover where the demigods from Percy Jackson meet the time - traveling heroes of Legends of Tomorrow. They could team up to stop a threat that spans across different timelines and mythologies. For example, a powerful ancient monster has been awakened in the future and is using time - travel to gain more power from the past. The demigods' powers and the time - travel abilities of the Legends would be combined to fight this foe.
Maybe there's a powerful magical artifact that has the ability to destroy both the Arrowverse and the timeline that the Legends protect. The two teams join forces to find this artifact before it falls into the wrong hands. They face numerous challenges and battles along the way, and some characters might have to make sacrifices to save the day.
An interesting plot for DC Legends of Tomorrow OC fanfiction could involve an OC who is a long - lost relative of one of the main characters. This OC might have been hidden away in time for some reason and now resurfaces with unique powers. Maybe they have the ability to communicate with past versions of themselves, which gives them an edge in understanding time - related problems. Or perhaps an OC who is a time - displaced artist. They use their art to record and sometimes even change events in time, causing the Legends to have to deal with these artistic alterations.
Maybe. Since it combines the spooky 'Ben Drowned' with the 'lemon' concept, there could be a plot twist where the relationship aspect is used to either save a character from Ben Drowned's wrath or make the situation even more dire. For example, a character might think they are in love with Ben Drowned only to find out it was all a ploy by him to cause more pain.
It's hard to say without actually reading it. But in many fanfics, there could be a plot twist like Amaru turning out to have a secret power that Naruto didn't know about and that power becomes crucial in saving the day.
One idea could be to explore an alternate timeline where the Legends accidentally change a major historical event in a way that creates a dystopian future. They then have to figure out how to fix it without making things worse.
One possible plot twist could be that Castiel kidnapped the character not out of malice but to protect them from a greater threat that the other characters are unaware of. For example, there might be a powerful and hidden enemy that has targeted this particular character, and Castiel believes that by taking them away, he can keep them safe.