Erza Scarlet is crucial. She's a powerful and fearless mage. Her backstory with the Tower of Heaven is really sad and it makes her character more complex. Makarov Dreyar, as the guild master, plays a big role in leading the guild and making decisions. And Happy, Natsu's flying cat sidekick, adds a lot of humor to the story. Without Happy, Natsu's character would seem a bit incomplete.
Natsu Dragneel is a must - include. His dragon - slayer magic is directly related to the dragons, and his fiery personality would add a lot of action to the story. Also, Igneel, Natsu's dragon father, could play a crucial role as his backstory is deeply intertwined with the Dragon Wars.
Well, it would likely include some of the witches from the 'Fairy Tail' world. But without actually reading it, it's hard to say for sure. There could be a lead witch character who has unique powers and a strong personality.
Natsu is often very popular. His fiery personality and powerful dragon - slayer magic make him a natural protagonist in many fanfictions. Writers like to explore his backstory further, especially his connection to Igneel. They also put him in various new adventures, like teaming up with unlikely allies against new and more powerful enemies.
Sanji is a key character. His cooking skills keep the crew fed and his chivalrous nature adds a lot to the story. Another important one is Robin. Her knowledge of the ancient Poneglyphs is vital in uncovering the secrets of the world in One Piece. Usopp also has his significance. His lies and his growth as a brave fighter are interesting parts of the story.
Eren Yeager is extremely important. He's the main protagonist and his journey from a young boy seeking revenge against the Titans to a key figure in the fight is central to the story. Mikasa Ackerman is also important. She's a highly skilled fighter and has a deep bond with Eren. Levi Ackerman is another crucial character. He's known for his incredible combat skills and leadership within the Survey Corps.
One of the most memorable is the Tartaros arc. It showed the dark side of the Fairy Tail world with powerful demons. The guild had to face great threats and there were some heart - wrenching moments like when some members seemed to sacrifice themselves. Another is the Alvarez Empire arc which brought in a large - scale war and really tested the bonds within the guild.
Natsu could be the most important. His impulsive nature might lead to him either taking quick action to change the future or causing some unforeseen problems while trying to deal with it.
Lucy is a very popular choice. Since she lives at Fairy Hills, there are a lot of possibilities for stories centered around her daily life there, her relationships with the other girls, and how she continues to grow as a mage.
Obviously, the main characters from the 'Fairy Tail' anime such as Natsu, Lucy, Gray, and Erza are likely to be the main characters in this fanfiction as well. Since it's about them watching the anime, they would be at the center of the story.
Fairy Tail is an anime about a guild of wizards who go on various adventures, facing powerful enemies and forming strong bonds along the way.