One consequence could be that his enemies might target Gordon to get to him. Since Gordon now knows his identity, if the bad guys find out, they could use Gordon as a way to harm Batman.
Well, Gordon's reaction could be complex. On one hand, he might feel honored that Batman has chosen to disclose his identity to him. On the other hand, he could also be worried about the implications. Knowing Batman's identity means he has a greater responsibility to protect that secret. He might start to think about how this new knowledge will affect their working relationship and the safety of Gotham. For example, if the wrong people find out that he knows Batman's identity, it could put him and his family in danger.
Merlin could face exile. Uther may not tolerate having a magic - user so close to him.
He could face Morgana's distrust if she takes his secrecy the wrong way. Maybe she'll think he has other motives for hiding his magic from her.
It could be a story where Alyx somehow gets transported to the Batman universe and teams up with Batman and Gordon. Maybe she has some unique skills or knowledge that helps them solve a big crime in Gotham.
One possible consequence is that Batman's loved ones would be in great danger. His enemies could target them to get revenge on Batman. Also, the public's perception of Batman might change. Some might see him as a hero who has been hiding his true self to protect them, while others could think he has been deceiving them all along.
The Riddler's daughter could be an interesting addition. She could be a brilliant detective herself, but conflicted about her father's criminal ways and her own feelings towards Batman.
One consequence could be that it changes the way his peers view him. If the fanfiction has some unique or unexpected ideas, it might make them see Naruto in a whole new light. Maybe it could even inspire some of them to start writing their own fanfictions. However, there could also be those who are critical and might tease him about it.
The theme of sacrifice also comes up. Both characters are willing to sacrifice a lot for the safety of Gotham. In some fanfictions, they have to make tough choices that show their commitment to the greater good. For example, Gordon might risk his career to protect Batman's identity at times.
One possible plot is that a new super - criminal has emerged who has the ability to create chaos in both Gotham and New York. This criminal has a plan to steal some high - tech items from Wayne Enterprises and Oscorp. Batman and Spiderman separately start to track this criminal. Gordon, on the other hand, is dealing with the local chaos in Gotham. Eventually, Batman and Spiderman meet in Gotham. There could be some misunderstandings at first, but they soon realize they have a common enemy. With Gordon's help in coordinating the police efforts, they manage to stop the criminal's plan.
One great 'Batman Barbara Gordon Fanfiction' is 'Oracle Rising'. It really delves into Barbara's transformation into Oracle. It shows her strength and intelligence in a way that's both engaging and true to her character.