James Potter's birthday was always a grand affair at Hogwarts. His friends, Sirius, Remus and Peter, would plan elaborate surprises. One year, they enchanted the Gryffindor common room to look like a Quidditch pitch, his favorite place. There were floating Snitches and mini - Bludgers. The whole Gryffindor house joined in the celebration, singing wizarding songs and sharing butterbeer. James was over the moon, his hazel eyes shining with joy as he thanked his friends for such an amazing birthday.
One interesting fanfiction could be where James Potter's birthday is celebrated at Hogwarts in a grand way. All his friends, including Sirius, Remus, and Peter, plan a surprise party for him in the Gryffindor common room. They decorate it with floating candles and his favorite Quidditch team banners.
You can start by looking on fanfiction websites like Fanfiction.net or Archive of Our Own (AO3). These platforms have a large collection of Harry Potter - related fanfictions, and you can simply search for 'James Potter birthday' in their search bars.
One common theme is family. Since it's James Sirius Potter, his family like his parents and siblings often play a big role in the fanfictions. For example, his father might give him an old family heirloom on his birthday.
One great 'James Sirius Potter birthday' fanfiction is 'James's Special Day' which beautifully depicts his birthday at Hogwarts with his friends and family. It has a lot of heartwarming moments.
A really interesting event in a James Potter birthday fanfic could be a wizarding photo exhibition. All the pictures from James' life at Hogwarts, his Quidditch matches, his pranks with the Marauders, etc., would be on display. His friends and family could walk through the exhibition and share stories related to each photo. There could also be a special section where people could write down their birthday wishes for James, and those wishes would magically float around the room like little fireflies.
Another challenge is in his relationships. He may worry that people pity him or treat him differently because of his blindness. For example, in some fanfics, he has to prove to Lily that he's still the same James she knew before, just with a new disability to deal with. Also, in duels or battles, not being able to see his opponents' movements directly puts him at a disadvantage, so he has to develop new strategies to defend himself.
He could meet the descendants of his friends, like the grandchildren of Ron and Hermione. They might show him around the future wizarding world and tell him about all the changes that have occurred. Also, he may run into some new and powerful wizards who have emerged in the future and learn from them about new magical techniques.
Perhaps James had some hidden magical ability that he was unaware of until that moment. It could be something that was passed down through his family but had never manifested before. This ability could have protected him from Voldemort's killing curse. Or, it's possible that there was a plot by some other characters to save James. There could have been a group of wizards or witches who had been secretly working to keep James alive because they knew his importance in the fight against Voldemort. They might have used some sort of time - turning magic or a protective charm that Voldemort couldn't break through.
One great 'Harry Potter James Potter' fanfiction is 'The Marauders' Era'. It delves deep into the friendship of James Potter and his friends. It shows their adventures at Hogwarts, like their pranks on Snape. The characters are well - developed and it stays true to the original Potterverse feel.