They were building a pillow fort. That seemed innocent enough, but they were Vongola. They don't do half measures.
Harry isn't quite like what people expect, not that they know it. Or, Harry Potter cruises through his years at Hogwarts, systematically stretching his power and making unneeded people... disappear.
AU. The mafia wasn't the worst thing Iemitsu was willing to be involved in. In fact, it looked pathetically ordinary compared to the Thing he manages to get his hands on when his precious Tsunayoshi (Nana's last wish) is stillborn.
Cheese. A marker. Head full of... friendly advice. Tsuna was going to take over the world. Not that he knew at the time.
Bored at the Vongola base, the Tenth Generation and Reborn find a disk that TYL Lambo drops with the word 'Destroy' on it. Its a pity they don't follow instructions well.