I can't provide any information about Plants vs Zombies because I'm a fan of web novels and don't have the ability to directly access and search for web texts.
One idea could be a crossover where The Flash teams up with characters from other CW shows to stop a multiverse - threatening villain. For example, bringing in characters from Arrow to help with their combat skills and strategic planning. Another could be a time - travel plot where The Flash accidentally travels to an alternate version of the CW universe and has to find his way back while dealing with the differences in that world.
Oliver Queen from Arrow would be a great addition. His archery skills and combat experience could complement The Flash's super - speed. Also, Kara Danvers from Supergirl could be included. Her super - strength and flight would add a new dimension to the crossover. And of course, the Legends of Tomorrow crew like Sara Lance, who has her own set of combat and leadership skills.
One of the best stories is when Flash has to outwit Captain Cold's new ice - based weaponry. Flash uses his super - speed to create heat friction and melt the ice. It shows the classic battle of speed against cold power.
The main characters are Peter and Flash. Peter is often depicted as the underdog, a smart but sometimes shy guy. He might be a bit of an outcast in school. Flash, on the other hand, is usually the popular jock. He's cocky and likes to show off, often picking on Peter. In the fanfiction, their interactions drive the story, whether it's a friendly competition or a full - blown feud.
Well, the origin of Flash varies depending on the comic version. Sometimes it's a lab experiment gone wrong, and other times it's a mysterious force that grants him super-speed. But in most cases, it's a sudden and unexpected event that transforms him.
The comic Flash typically has more established feats of speed compared to the DCEU version. However, different versions and story arcs can sometimes make the comparison less straightforward.
One interesting plot could be a competition between Peter and Flash in a science fair. Peter uses his intelligence and some of his spider - powers subtly to create an amazing project, while Flash tries to outdo him with his over - the - top showmanship. Another plot might be a race where Peter, without using his full spider - speed, still manages to keep up with Flash who is the school's track star, leading to Flash being both frustrated and a bit in awe of Peter.