It could mean that a particular dream or vision is no longer just a work of fan - created fiction. Maybe it has become something more real or has evolved beyond the realm of being a fan - based fictional idea.
Well, without reading it, it's hard to say for certain. 'A dream no longer Ben 10 fanfic' could imply that it was a fan - created story inspired by Ben 10, but then it took a turn away from that. It could be that the author had an initial concept that was very much in the Ben 10 universe, but as they wrote more, they decided to go in a different direction that no longer held the same elements of the Ben 10 franchise. It might involve new characters, new settings, or a completely different plot that breaks away from what is typically associated with Ben 10.
Sure. Let's say someone had a dream of writing a story set in the 'Harry Potter' fanfic world. But then they realized they could create their own magical world with its own unique rules, characters, and storylines. So their dream of writing a story is no longer a 'Harry Potter' fanfic but an original magical story. That's an example of a dream no longer fanfic.
Well, first of all, die - hard Ben 10 fans who are always on the lookout for new interpretations of the franchise might give it a shot. They might be intrigued to see how the fanfic has deviated from the norm. Then there are those who are fans of science - fiction and fantasy in general. They might be attracted to the idea of a story that has its roots in the Ben 10 world but has now branched out. Additionally, readers who like to explore the creative process of writers, seeing how a story can start in one place and end up in a completely different one, could also be interested in 'a dream no longer Ben 10 fanfic'.
Perhaps it implies that someone's aspiration or daydream has outgrown the status of being a simple fanfiction. For example, if a person had a creative idea inspired by a fandom at first, but now it has developed into something more original and substantial, so it's no longer just fanfiction - like. It might be an idea for a new project or a new way of thinking that has its own identity now.
Here's another example. There was a group of fans who were into a science - fiction TV show and they had fanfiction - like dreams about time travel within that show's universe. But then, one of them used those initial ideas as a springboard to develop a new screenplay about time travel in a completely different setting, with different characters and a different take on the concept. In this case, that person's dream has transitioned from being fanfiction to something more unique and original.