Because you like Ganondorf (Ganon) in The Legend of Zelda
Kenzo Tenma would have never guessed that ten-year-old he saved would later become a deadly serial killer intent on "thanking" him. See them in Monster (TV Show).
Herion is Mark Renton's favorite drug. He sniffs it, smokes it, swallows it, sticks it up his arse, and injects it into his veins. See them in Trainspotting.
The Ice King is lonely and looking for a princess to sweep him off his feet. See them in Adventure Time.
Eliot Waugh is the unspoken leader of his group of friends at a school for magic. See them in The Magicians.
Logan Huntzberger is a daredevil, romantic, and heir to a media empire. See them in Gilmore Girls.
China has five thousand years of history, and he's optimistic he'll win over the Allied Powers to the wisdom of his ways. See them in Axis Powers Hetalia.
Shuri is a genius-level inventor with a wicked sense of humor. See them in Marvel Cinematic Universe.
When push comes to shove, the usually overly cautious Luigi has the heart of a hero. See them in Super Mario Bros..
Lady Macbeth takes being a powerful woman to a whole other level. See them in Macbeth.
Rainbow Dash's interests include flying, playing pranks, and generally being themost awesome pony around. See them in My Little Pony.