Well, it can be appropriate if it is written within the boundaries of respect and positive storytelling. For example, if it focuses on building a healthy relationship between the characters in a non - offensive way.
Yes, there are quite a few out there. You can start by looking on popular fanfic websites like Archive of Our Own. Just search for 'luffy x lucy heartfilia' and you'll find a variety of stories with different plotlines and writing styles.
I'm not sure if there is a specific 'lucy x sting' fanfic rated M. You could try searching on popular fanfic websites, but make sure to follow their terms and conditions.
One common theme could be friendship. They might start as friends and then develop deeper feelings. Another could be adventure, where they go on quests together.
Friendship is a major theme. Since they are both part of the Fairy Tail guild, their bond is explored, whether it's just a normal friendship or something deeper.
One common theme is adventure. Since Luffy is an adventurer in One Piece and Lucy has her own adventures in Fairy Tail, it's natural for their fanfics to involve them going on exciting quests together.
Another theme could be growth. They both could grow as individuals, learning from each other's strengths and weaknesses. For example, if End is brave but impulsive and Lucy is cautious and intelligent, they can balance each other out. This growth can be both in terms of character and in their abilities. They might face challenges that force them to adapt and become better versions of themselves.
One possible plot could be a story of End and Lucy going on an adventure together. They might discover a hidden world full of magic and mystery. Along the way, they face challenges that test their friendship and courage.
Yes, there are quite a few. You can start by looking on fanfiction platforms like Archive of Our Own. Some fanfics might focus on their unique friendship dynamic, exploring how Charlie Brown's perpetual optimism interacts with Lucy's more cynical nature.
One common theme could be adventure. Since they are often from a fictional world with potential for action and exploration, fanfics might feature them going on quests together.