Well, it could be about Natsu being accidentally or deliberately left in a certain place. Maybe his friends go on a mission without him, and he has to find his own way back or prove himself while being left behind. It might also involve his feelings of abandonment and how he overcomes them.
Obviously, Natsu would be one of the main characters. Since it's about him getting left behind. His friends from his usual group like Lucy, Gray, and Erza could also be important characters, even if they are the ones who leave him behind at the start. There might also be new characters introduced in the fanfiction that Natsu meets during his time alone.
Well, it could be about Natsu being left behind in Tenrou. Maybe it's a story where his friends accidentally leave him there during some sort of event or mission. It might explore his feelings of isolation and how he tries to find his way back to them.
Obviously, Natsu would be a main character since he's the one left behind. There could also be other characters from the original series who are relevant to the story, like his friends who left him, such as Lucy, Gray, and Erza. Maybe some local characters in Tenrou could also play important roles in the fanfiction.
In this kind of fanfiction, they might face various challenges. Maybe they'll have to find their way back on their own. They could encounter dangerous magical creatures and have to rely on their own skills and the bond between them to survive.
The main characters are clearly Natsu and Lisanna. Natsu is a well - known character with his fiery personality and powerful dragon - slayer magic. Lisanna is also important, she has her own set of skills and a unique relationship with Natsu.
In this fanfiction, they might have to face a series of challenges alone. Maybe they'll encounter powerful enemies that they have to defeat without the help of their usual comrades. They could also discover new powers or abilities within themselves during this time of being left behind.
It's Natsu and Erza. Natsu, the energetic dragon slayer, is always ready for a fight and has a great sense of loyalty towards his friends. Erza, with her strict yet caring nature, is a force to be reckoned with. In this fanfiction, their individual skills and personalities will likely be explored more deeply as they are left behind.
He could marry an original character created specifically for the fanfiction. This character could be a powerful mage from a far - off place who crosses paths with Natsu during one of his adventures.