A Sword in A World of Flames {Fate/Stay Night UBW x Katekyo Hitman Reborn!}

Several years after Shirou and Rin Tohsaka won the Heaven's Feel Tournament the Moonlit World was discovered by governments across the world. In a last act of desperation to prevent the worlds of the mundane and magi from destroying themselves in all-out war. Shirou attempts an assassination of the leaders on both sides. Leading her to be hunted down by both worlds as an international criminal.
Inevitably her pursuers catch up to her. Confronted by a saddened Rin Tohsaka, Shirou asks her best friend to kill her. But unknown to both of them, Rin's wish for her best friend's happiness was granted...by the multiverse's #1 troll; Kishor Zeltretch von Shwienorg.
Instead of Shirou's soul ascending to the Throne of Heroes as an Anti-Hero, the user of Kalidoscope reincarnates her into a parallel world. One where magi continue to exist but aren't the leading mystic power. That honor goes to the Dying Will Flame users of the Mafia.
This new world that Shirou's born in is both less dangerous and more dangerous for the Incarnation of Sword. But then again...her bi-polar luck and newfound allies in the form of her older sister Illyasveil von Einzbern and her childhood friend, Tsunayoshi Sawada. A brunette that wouldn't know the meaning of studying even if it hit him on the head.
When the world turns itself on its head with the arrival of an infant that's dressed in a suit and smells of gunpowder, coffee, blood, and sunshine. Shirou, Illya, and Tsuna's rather peaceful lives turn on its head.
Only one thing Shirou can say when it comes to her bi-polar luck and a certain Kalidoscope. "ROOT DAMN MY E-RANK LUCK!! DAMN YOU ZELTRECH!!!!"

*Note: I DO NOT own Fate, nor KHR
*Irregular updates