One common theme is friendship. When Sam and Dean meet Max, often a new friendship forms and they learn to rely on each other. Another theme is discovery. Max might introduce them to new places or ideas.
A major theme is the exploration of different realities. Since Sam and Dean are fictional characters and Jared and Jensen are real - life actors, fanfictions often play with the idea of how these two different existences can interact. Also, humor is a big part of it. The misunderstandings that occur when they meet usually lead to some really funny situations, like Sam and Dean thinking Jared and Jensen are some sort of magical doppelgangers.
One great 'sam and dean meet max fanfiction' story is 'The Unexpected Encounter'. In it, Max's character adds a whole new dynamic to Sam and Dean's adventures. The story is full of action and mystery as they team up to fight a common enemy.
Sam is more cerebral and often tries to find peaceful solutions. Negan, on the other hand, is brash and used to getting his way through force. So Sam would likely be put off by Negan's aggressive nature. Dean is protective and hot - headed. He would not tolerate Negan's threats easily. So their personalities would clash as Sam tries to reason and Dean is ready to fight against Negan's overbearing attitude.
One possible plotline could be that Negan initially tries to assert his dominance over Sam and Dean. He might see them as a threat to his own 'rule' in the world of the fanfiction. But Sam and Dean, being the hunters they are, would not take kindly to his posturing. They could end up in a battle of wits and strength. Another plotline could be that Negan has some information about a powerful supernatural entity that Sam and Dean are after. So they have to form an uneasy alliance. Sam might try to reason with Negan while Dean is more on the side of being cautious and ready to fight if needed.
Well, in a fanfiction where Sam and Dean meet Max Guevera, there could be a lot of action. Maybe Max's superhuman abilities would come in handy when they face some common supernatural foes. She could help them out in a fight against demons or vampires. For example, her enhanced strength and agility could turn the tide in a tough battle.
One possible plot could be that Sam and Dean are pulled into an alternate universe where they meet Jensen and Jared, who are actually aware of the Winchesters' story. They could team up to fight a new, powerful supernatural threat that exists in this strange new world.
There's a great piece of fanfiction called 'Behind the Scenes Meeting'. In this story, Sam and Dean are transported to a convention where they meet Jared and Jensen. It's really cool because it shows how the two groups interact, with Sam and Dean being a bit confused at first about who these people are who look just like them in a different way. The author does a wonderful job of creating humorous and heartwarming moments throughout the story.
Their meeting might also be a catalyst for character growth, which in turn affects the plot. Sam and Dean could become more open - minded because of Max, and this could lead them to take on different types of cases or approach their existing cases in a new way. For example, they might start to consider the ethical implications of their actions more deeply, which could change the decisions they make throughout the story.
Jensen could be shown as being very in - character as Dean Winchester, even when he's himself. He might have a cocky charm and a quick - witted sense of humor. Jared could be the big - hearted, gentle giant type, similar to his portrayal of Sam on the show. He's friendly and eager to learn about the real Sam and Dean, while also sharing stories from his time on the set of Supernatural.