Okay, I'll give everyone an example:

Lucy quit Fairy Tail because no one talked to her after Lisanna came back.

What.

Are you kidding me?

The whole theme of Fairy Tail is "nakama", or "family".

Nakama stick together and help each other.

That's what the anime says, among other things.

Stick to the theme, fellow authors.

It's important.

Unless you're doing a drastically different AU, you must always stick to the theme.

Unless this new theme fits the story.

Also, I don't own Fairy Tail or its characters.