Another great choice could be Laxus. He has that tough - guy exterior but also a lot of room for character growth. In a fanfiction as guild master, he could bring a different leadership style, more aggressive perhaps. He might change some of the guild's traditions while still maintaining the core values of Fairy Tail. He also has a great relationship with his team, which could be further developed in the fanfiction.
A plot could be about a new guild master having to deal with a powerful dark guild threat. The new guild master, say someone like a new character introduced in the fanfiction, has to unite the Fairy Tail members, who are initially skeptical of their leadership. They have to come up with new strategies to combat the dark guild's unique magic and overcome internal differences within Fairy Tail.
Weapon Masters would usually receive missions from the Mithril Guild. These missions usually involved protecting important people or carrying out certain dangerous missions. Weapon Masters were usually very excited because they had the opportunity to showcase their professional skills and strength, as well as the opportunity to earn a lot of wealth and reputation.
Kakashi could be a great guild master. He's already a highly skilled and respected ninja in the Naruto world. His knowledge of various jutsu and his experience in leading teams would make him a natural fit for the role of guild master.
I recommend " The Quickwear Animation Mission." The protagonist of this novel can complete missions in the animation world and save the animation world. The missions included becoming cute pets, protagonists, and passersby. Moreover, if the mission failed, the handsome man would help complete the mission. I hope you like this novel.
Such novels were generally known as " swordsmanship novels." The protagonist usually had extraordinary swordsmanship abilities and learned various sword techniques. In the novel, the protagonist often participated in various battles to challenge various powerful enemies and constantly grew and improved in the battle.
These novels usually involved some mysterious magic power or legendary divine weapons that made the protagonist's swordsmanship even stronger. At the same time, the protagonist's character and wisdom would also become an important element of the story. Sometimes he would become a hero, sometimes he would be in danger, but he would always be able to overcome difficulties and eventually become a legend.
Swordsmanship novels were very popular online and often attracted a large number of readers.
One interesting storyline could be the guild master leading the Naruto characters on a new and dangerous mission outside of the main Naruto plot. Maybe they are exploring a mysterious land filled with unknown ninja techniques.
The dark guilds would be great antagonists. They might see Natsu's new leadership as a threat and try to undermine his guild. They could send their best mages to disrupt the guild's operations and steal important magical artifacts.
Maybe in the 'natsu guild master fanfic', Natsu becomes guild master during a time of crisis. A dark magic is spreading and threatening all the guilds. Natsu has to make difficult decisions, like forging alliances with former enemies. He uses his fiery determination to inspire his guild and they fight back the dark forces together. He also discovers new aspects of his magic along the way to better protect the guild.
In many 'natsu 4th guild master fanfiction', the theme of change is prominent. The guild will surely change under Natsu's leadership. There's also the theme of responsibility. Natsu has to be responsible for the well - being of the entire guild now. And often, there's a theme of legacy, as he is following in the footsteps of previous guild masters and has to make his mark on the guild's history.