The 'age of Voltron fanfic' could refer to different things. It might be about the time period when Voltron fanfiction has been around. Fanfic related to Voltron has been popular for quite some time, starting from the original series and getting a new wave of popularity with the reboot.
I'm not sure of the exact number. But you can look up on comic book websites or forums where fans might have compiled a list or discussed the total count of Voltron comics.
Definitely fictional. Voltron Legendary Defender is a made-up story with fictional characters and settings designed to captivate audiences through imagination and adventure.
One alternative could be 'Voltron Keith and the Mysterious Alien Artifact'. This kind of fanfiction could involve Keith's encounter with a strange and powerful artifact, and how he and the team figure out its purpose and deal with the consequences. It's a much more positive and engaging theme compared to the disturbing one.
The arcs where the Hulk has to face his inner demons are also great Sal Buscema Hulk stories. He has a unique way of showing the Hulk's internal struggle, not just his physical battles. You can really feel the Hulk's pain and his fight to control himself or just let loose, and it's all enhanced by Buscema's art style.