A possible plot could be that there is a magical competition in the League of Legends world. Lulu and Veigar both enter. At first, they see each other as rivals. But during the competition, they face a common enemy who is trying to disrupt the event. They then team up, combining Lulu's whimsical magic and Veigar's dark magic to defeat the foe and in the process, form a unique bond.
Their relationship could start with curiosity. Lulu, being the curious fae, might be interested in Veigar's dark magic. Veigar, on the other hand, might be intrigued by Lulu's ability to manipulate nature with her magic. This initial curiosity can lead to them spending more time together, gradually understanding each other.
Perhaps there is a powerful enemy that exists in both universes. Naruto and Lulu, through some magical or chakra - related means, are made aware of each other's existence. They meet and combine their unique powers. Lulu's magic and Naruto's ninjutsu could create some really cool and unexpected combat techniques, like using Lulu's polymorph spell on Naruto to give him a new form with enhanced ninja abilities.
One interesting plot idea could be Ryan and Lulu having to work together on a top - secret project at True Jackson VP. They start off bickering as usual but gradually discover they have more in common than they thought and form a strong friendship. Another could be a time - travel plot where they are sent back to the early days of the company and have to make sure things happen the way they're supposed to for the present to be intact. A third idea is that they get accidentally swapped into each other's bodies and have to navigate each other's lives for a day, leading to hilarious and heartwarming moments.
Maybe X - 23 is on the run from some anti - mutant forces and finds herself in Gotham. Batman initially suspects her but then realizes she's being hunted unjustly and decides to help her. They then have to fight off the hunters while also dealing with Gotham's regular villains.
A plot where 707 and MC get trapped in a virtual world that is a distorted version of their own reality. They need to find a way to escape by solving puzzles and relying on each other's unique skills. For example, 707's hacking abilities could be crucial in finding glitches to break free.
A more complex plot could be that there is a misunderstanding between Stitchpunk 1 and Stitchpunk 2. Stitchpunk 1 thinks Stitchpunk 2 has betrayed the group. As they try to resolve this issue, they uncover a conspiracy within their community that they must work together to stop. This would involve a lot of character development and exploration of their relationship.
One idea could be that the OC is a healer who stumbles upon Frankenstein's monster in the woods. The OC decides to help the monster, despite the danger, and they form an unlikely bond. This could lead to a story of redemption for the monster and a journey of self - discovery for the OC.
A plot could revolve around Sesshomaru being intrigued by Naruto's determination. Sesshomaru decides to train Naruto in some of his own combat techniques, which Naruto adapts to his own fighting style. In return, Naruto shows Sesshomaru the value of friendship and loyalty within a village. This could lead to Sesshomaru having a change of heart about his own solitary ways. Also, they could team up to face a common foe from Sesshomaru's world that has somehow entered the Naruto universe.
Maybe the OC is a scientist who has developed a device that can temporarily steal The Flash's speed. At first, the OC uses it for personal gain, but then realizes the chaos it's causing in the city. They then team up with The Flash to take down other villains who are after the device. Or, the OC could be a meta - human with the ability to see the future in flashes. The Flash initially doesn't trust the OC, but as they start to have the same visions, they have to work together to prevent a major disaster from happening.
A plot could involve the reader being a healer of sorts. Flowey, being curious, approaches the reader. As they interact, the reader starts to show Flowey kindness that he's not used to. This kindness begins to thaw his cold, calculating nature. They could then go on adventures together in the Underground, with Flowey slowly becoming more protective of the reader. Also, the reader could introduce Flowey to new concepts like friendship and self - sacrifice, which would be a huge change for him.