Black butler 1: Ciel
The hat found itself subtly impressed with the mind beneath it. It had never before come across a thought process so complex yet well organised. The boy was smart, advanced well beyond the year he was entering. He was also incredibly brave and willing to risk many things if he thought it would be of benefit, and mixed into the lot was a cunning and strength that meant he could easily use both of those traits to the best advantage.
Then there were the boy's morals. The hat had found that darker wizards tended to find a more accepting home in Slytherin, while people with similar traits but lighter tendencies were occasionally shunned in the same house. Over the centuries the hat had gotten good at sorting so that all students were more likely to find a home.
That ability was being tested to its very limits.
The boy had darkness, lots of it, and a supreme lack of value of human life carved into him over months of experiencing the worst of human kind. And yet he had never truly managed surrender entirely to the dark, he held a purity that called for the sparing of innocence from pain and suffering.
In short the tiny child was one giant contradiction. He managed a perfect balance between all the house traits, walked the thin like between both light and dark.
There was absolutely no way it could make the decision of where to put him.
'Just send me wherever I am least likely to experience annoyance at my house mate's actions,' the boy commented when he realised the hat was unable to decide.
'RAVENCLAW,' the hat shouted.
Ciel ended up rather pleased with his placement. Like when he was in the blue house at Weston College the rest of the house was too busy studying to pay attention to his extra activities as he investigated the rumours that had Her Majesty concerned.
When people told the hat later what the boy had managed to accomplish it would wonder (but only ever to itself) if the better choice may have been Slytherin after all.