I'm not entirely sure if it's a popular genre. Fanfiction can cover a vast range of themes, and while there may be some works with such themes, it might not be mainstream. The Black Clover fanfiction community has a lot of different types of stories, from adventure and friendship to power - up scenarios.
Celestial grimoire fanfiction might be centered around a grimoire that has celestial or otherworldly powers. Fanfiction writers could take this concept and run with it. They might create stories where the grimoire is a key to unlocking secrets of the universe, or perhaps it's being hunted by various factions in a fictional realm. It could also be about a hero or heroine who discovers the grimoire and has to learn to control its power.
Black Clover tells the tale of Asta's journey to become the greatest mage. It's full of magic, friendships, and intense battles. Asta's perseverance and the complex web of relationships make it an engaging story.
Yes. The Black Clover light novel offers additional insights and background details that aren't present in the main series. It's a treat for fans who want to delve deeper into the world.