There could be a mysterious old wizard who takes Natsu under his wing when he leaves Fairy Tail. This wizard might have knowledge of ancient magics that Natsu is eager to learn.
Another interesting plot could be that Natsu leaves Fairy Tail to follow in the footsteps of a long - lost relative who was also a powerful mage but had some sort of connection outside of the guild. Along the way, he meets new allies and enemies, all while the Fairy Tail members are trying to bring him back.
I really like 'Etherious Natsu's Adventure'. This fanfic takes Natsu on a journey where he has to face some of the darkest secrets of his past as an Etherious. It's well - written with a lot of action and emotional moments. For example, there's a part where Natsu confronts a figure from his forgotten past, and the way it's described is really engaging.
Gray would be shocked at first. He and Natsu have a long - standing rivalry - but also a deep friendship. He might initially be angry that Natsu would just leave like that, but then he would realize how much he'll miss him. He might also feel a sense of loss for the guild as a whole, since Natsu is such an important part of it.
Well, in these fanfictions, the concept of the Etherious is really interesting. It allows for a lot of creative exploration. For instance, we can see different interpretations of how Natsu's Etherious nature affects his relationships with other guild members. Some fanfictions show him having to struggle with his darker side, which makes for a great read. Also, fans love to see Natsu in new and exciting situations that the original series might not have covered, like facing ancient evils related to his Etherious origin.
One interesting natsu leaves fairy tail fanfiction could be about him going on a solo adventure to discover his true power. He might face challenges that he couldn't in the guild and grow in ways unexpected. Maybe he meets new characters who teach him different forms of magic.
Well, in fanfiction where Natsu leaves the guild, he could become a sort of lone wolf. He might travel to far - off lands to discover more about his dragon - slayer powers or his past. This could lead to him meeting new and powerful allies or enemies. Without the support of the guild, he would have to rely solely on his own strength and wits. It could also make him a more serious and hardened character, as he no longer has the safety net of his Fairy Tail family.
One possible plot could be that Natsu and Erza leave Fairy Tail due to some kind of internal conflict within the guild. Maybe there are differences in opinions regarding how the guild should be run or what kind of jobs they should take. So they decide to set out on their own journey to find a new purpose.
It could be a group of rogue mages who have a vendetta against Natsu and Erza. They see the two leaving Fairy Tail as an opportunity to attack them when they are more vulnerable outside the protection of the guild.
One possible storyline could be that the OC tries to find Natsu after he leaves Fairy Tail. The OC might have a special bond with Natsu and be determined to bring him back. They could go on a journey where they face various challenges and meet new characters along the way. Another idea is that the OC is actually the reason Natsu leaves Fairy Tail in the first place. Maybe there was a misunderstanding or a conflict between them that led to his departure, and the story could be about how they resolve it.