Let's try this, all the women of Fairy Tail are in Mermaid Heel, Natsu, a courier, has a chance encounter with these Mermaids...I think we see where this is going. NatsuxHarem.

Natsu and Happy always kept their true strength in secret, but after a chance encounter with a certain female, they might not need to do so anymore. Though, one bad day is enough to change ones live, including a certain Dragon Slayer. Fairy Tail has more trouble as a dark guild has declared war with them. Will they win? Smarter Natsu. OP Natsu and Happy! Strictly Natsu X OC (AU)

"I don't care about taking over the world. I don't care about revenge. I don't care about stupid people in stupid costumes. All I really care about is protecting my master and what she wants, even if it annoys the crap outta me. But that doesn't mean I'll turn down a challenge in any shape. I ain't the strongest demon in the Underworld for nothing after all." NatsuxCircexHarem

In a freak accident of technology and magic, Natsu is blasted into Edolas while Edo-Natsu is transported to Earthland. Now Fairy Tail must figure out how to switch them back. Lucy is put in charge of protecting timid Fireball Natsu and discovers his bashful side is "rather cute." Meanwhile, Natsu faces trouble with Lucy Ashley and the guild in Edolas.

Can fortune repeatedly fall on one person's hands? Meet Natsu Dragneel, a man who has the perfect luck, someone who makes every man envy him and who is always surrounded by beautiful women. Smut story and Lemon fic

Natsu Dragneel convinced Gildarts to take him on his Century Quest and to train him to become stronger than any other, upon his return Natsu is a changed man having experienced the harshness of the magical world. Follow Natsu as he discovers higher realms of power as he strives to rise above both the Gods and Devils themselves as he fights to save the ones he loves.

"Wait!" Natsu reached through the flames his hands moving towards the retreating figures of his mother and sister. For the last time his mother faced him, her brown eyes full of hate. "Just stay where you are, Monster" Tears welled up in his eyes soon evaporated by the heat. He gave his sister a pleading look however she looked away, fear evident on her face. AU! Hollow Natsu!

how would it be if Natsu when the baby was first discovered by Irene? not Igneel / sorry not good at making summary (Announcement: It takes two Beta Reader to correct my mistake in writing and for those interested please PM)