Disclaimer: I do not own Fairy Tail, or any of its associated characters and lore. That right belongs to Hiro Mashima.
[MDGH]
The Moon Dragon Goddess in Hargeon
[MDGH]
Hargeon Town, Kingdom of Fiore, Ishgar, Earth Land, July 2, X784
Having secluded herself to the continent of Guiltina alongside the other Dragon Gods, Selene the Moon Dragon God had not ventured to any other place on Earth Land in centuries, and in the event she did feel restless in the same place, she had used her Moon Dragon Slayer Magic to observe and directly visit other dimensions such as the Magically-lacking Edolas and its opposite of Elentir, but after four hundred years since Acnologia's rise to power, Selene had decided to pay a visit to a different place on Earth Land mostly on a whim.
While the Town of Hargeon was not home to many Wizards, let alone one that could pique Selene's interest, it was during her stroll on the streets as she avoided numerous lecherous glances to her Human form that she heard excited murmurings of a "Salamander", an apparently famous Wizard residing in Fiore, being not so far away. Even as she rolled her eyes at how foolish the local women were being, Selene nonetheless decided to catch a peak at this person since she had nothing else to do then.
Upon glancing the blue-haired man, who was using Charm Magic to win the female crowd in a way that was clear to one of Selene's power, she knew that the imbecile was not worthy of any truly powerful being's attention. While Selene could tell from both her senses and her insightfulness that "Salamander" had a more malicious goal in mind for this flirting, she decided to move away, not seeing what would become of the Human females being her responsibility.
It was right then, however, that Selene's senses of smell and hearing picked up curious signs from someone that she knew would entertain her for sure.
With a wide smirk, she quickly chanted. "Transfer." In a flash, she teleported from one side of the lovestruck crowd to the other just before a pink-haired young man brushed past a curvaceous yet Charmed blonde. "Hold it." Selene commanded with her hand raised in front. Seeing the young Wizard look at her curiously yet recognizing that she was indeed powerful, Selene added with a seemingly friendly smile. "May we have some words together?"
[MDGH]
Local Restaurant of Hargeon Town
When Natsu Dragneel and his talking cat companion, Happy, had come to Hargeon on a potential lead to Igneel, he was not expecting to be held back from his search by a strange, yet beautiful, woman with long, pale blonde hair and pink eyes who seemed to have been attired in the kimono garb of a shrine priestess. However, something told Natsu that the woman, Selene as she referred to herself, was not what she appeared to be and decided to hear her out for the sake of argument. That the three of them enjoyed a good lunch was a bonus as well.
"So let me get this straight." Natsu said in between bites as he heard what Selene was telling him about the "Salamander" in Hargeon that he assumed was Igneel. "There's a Human calling himself Salamander rather than a Dragon being called a Salamander?"
Smiling at Natsu's deflated expression, Selene replied. "In all honesty, it would have made bigger news if a genuine Dragon did come into these parts. But have no fret, Natsu, I believe Igneel is much closer than you think."
Perking his attention at the name, Happy stopped eating his fish and spoke before Natsu could. "How do you know about Igneel, Miss Selene? I don't think we told you about that."
Gently petting Happy on the head, Selene answered with a pointed gaze on Natsu. "In a way, young Exceed, Natsu and I share certain things in common. The use of a Dragon's Magic being one of them."
"You're a Dragon Slayer?" Natsu asked with widened eyes, pushing away the odd term she called Happy.
Selene laughed in an innocent way as she then said. "I'm a lot more than that, Natsu. Far, far more in fact."
Before Selene could go into detail, a waitress passed by to deliver a check at their table. Looking over it, Natsu said with a grimace. "I shouldn't have ordered so much food for us, after all." But was reaching his pockets for money when Selene interjected with a devious grin.
"Come now, Natsu, would it really be such a terrible thing if we, as they say, dined and dashed?"
Looking at her skeptically, Natsu replied. "I don't know. I guess the old man would deal with it later, even if he would be unhappy about it, but how would we get out of here so fast, anyway?"
Smirking, Selene answered. "Allow me to demonstrate." And with a snap of her fingers, all three of them had vanished from the restaurant, and then reappeared in Hargeon's park.
"Wait, what?!" Happy was exclaiming in shock. "What kind of Teleportation Magic was that?!"
Laughing once more, Selene was about to say something when she then directed her gaze to a gossiping duo of girls that were conversing, according to both her and Natsu's advanced sense of hearing, about the Wizard "Salamander" being a well-known member of the Fairy Tail Guild, which immediately got Natsu's attention.
"Salamander's a member of Fairy Tail?!" Natsu stated in abrupt anger. "He's lying! I don't know anyone by that name in the guild!"
"Or perhaps it's an alias?" Selene asked him with an eager expression. Seeing Natsu and Happy look confused, she explained. "As I understand it, it's common to grant prominent people, especially Guild Wizards, a kind of callsign based on what they do, their abilities, or some other definition."
"Oh, I get it, Natsu." Happy said. "It's like how Erza is called Titania the Queen of the Fairies."
Scratching the back of his head, Natsu replied. "I guess, but I don't see how Macao could be called a "Salamander". And he shouldn't be here, so it must be an imposter still."
Selene then interjected with a knowing smile. "Isn't a mythical Salamander supposed to be a fire-breathing creature similar to a typical Dragon, but different?"
"Yeah, that's why I figured it was Igneel, but what does that have to do with Fairy Tail?"
While Natsu pondered over that line of thought, Happy's eyes widened, and he exclaimed. "Natsu's the one who's being impersonated?!"
"Huh?! I am being called Salamander by the masses?! Why wasn't I told?!"
Laughing at their outrageous expressions, Selene then told them. "Considering that the imposter had gone to a great deal of trouble to impersonate you, Natsu, I can only imagine what kind of goal he has in mind for all the local women he's socialized with. Care to get to the bottom of it?"
Narrowing his eyes in determination, Natsu said. "You don't have to tell me twice. Nobody makes a mockery of me or my guild, even if they had permission to do it."
Humming in interest, Selene brought her face closer to plant a kiss on Natsu's lips and said to the surprised and blushing Dragon Slayer. "Think of it as an unnecessary, but well-liked good luck charm." With a snap of her fingers, she quickly added just as Natsu and Happy were Transferred elsewhere. "May we meet again."
[MDGH]
After this, I can imagine that Selene would make sporadic appearances throughout the first Fairy Tail story to offer some pointers to Natsu and friends, while sitting on the sidelines mostly for her own entertainment, like a "watch the series" story, but more interactive and sensible, which actually would make for a good longer story. I know Selene is not high on most Fairy Tail fans' popularity lists right now, but I like her still and it would be nice if she had hidden depths to her character.