The name of the game is simple. Name an out of character idea or personality trait you think will make a great story.

My ideas are having Rainbow Dash get into fashion while keeping her in character.
Write a shipfic of Button Mash and Sweetie Belle without actually shipping them. (don't judge me!)
Introduce Filthy Rich's disdain against the Apples without making him unpleasant. Think two-face or something.
AND have Diamond Tiara show her cowardly moe side to the CMC without writing a shipfest! (I thought of Mio from K-On when I wrote this.)

My questions are...
How can I turn these ideas into short summaries?
What would be your out of character challenge? And how would you write it?