How would the bat family members react when they find out about slade fanfiction?

Well, they might be really shocked at first. Batman, for example, would probably be concerned about how Slade is being portrayed in this fanfiction and whether it has any negative impacts on their 'relationship' in the public eye of the Gotham world.

Dick would probably be excited. He loves the idea of fans being so engaged with their world and would enjoy reading the different takes on their relationships. He might even leave positive comments if he could.

They'd be surprised. The more innocent ones like Tsuyu might just blink in confusion. And Todoroki might raise an eyebrow, not fully understanding what it's all about.

Some members like Itachi might be very calm and just observe quietly. He would probably analyze the stories, thinking about how the characters are developed and what the underlying themes are.

Thor would be quite confused at first. Fanfiction is not something from Asgard. But once he gets the gist, he might say something like 'This is a strange Midgardian custom, but if it shows the great friendship of Steve and Bucky, then it is not all bad.' Meanwhile, Tony would be all over Steve, making snarky comments and asking if he's finally going to admit to some hidden feelings for Bucky according to the fanfiction.

Superman might be a bit amused. He'd see the Naruto characters' struggles and compare them to the challenges he faces in Metropolis. Batman would probably study it like he does any case, trying to figure out the motives of the characters in the fanfiction. Wonder Woman would likely be drawn to the strong female characters in Naruto fanfiction, if there are any.

Robin would probably stay calm and observant. He's been trained well, so he'd immediately start looking for any weaknesses in his captivity situation. He might try to pick the locks on his restraints if he's bound, or find a way to communicate with his team secretly if there's a chance.

In many fanfictions, the Avengers' reactions vary. Tony Stark might be proud, like he's found a protege. He'd probably start upgrading Peter's suit right away. Captain America, on the other hand, would be more concerned about Peter's moral compass and whether he's ready to be a full - fledged Avenger. Hulk might not care much at first, but once he sees Peter's strength, he could become his ally. Overall, it's a mix of different emotions and actions.

They might be shocked and confused. It could lead to a lot of internal conflict and soul-searching among the team.

Some of their friends might be shocked at first. For example, Gray might do a double - take and be completely speechless for a while. But then he would probably be happy for them in the end. Lucy would likely be overjoyed and start asking a million questions about how it all happened and when. Happy would be flying around them in circles, squealing with excitement.