"Reborn, my love, I don't know how I would survive without you," Tsuna murmured, stroking the picture of the hitman.
He set down the picture and picked up a stack of paperwork. While carrying the stacks, he walked to Reborn's office, where his intuition was telling him Reborn was at. Tsuna quietly opened the door as saw a magenta-haired woman straddling the hitman, who was smirking with his hands on her hip. Disgusted by the sight, Tsuna left the papers in the floor and went to his room. He gazed at his full-body mirror.
"Natsu," he breathed.
"What's up?" his reflection asked.
Tsuna examined his reflection. His reflection changed to have lighter and narrower eyes, but other than that, he looked the same.
"Bianchi is with Reborn. How do I get Reborn to myself?" Tsuna mused.
Natsu and Tsuna shared a smirk.
"Get rid of all competition," they sang together.

Bianchi blinked. The last thing she remembered was sleeping with Reborn. She looked around her surroundings. Nothing but pitch black. As an assassin, Bianchi was trained to use all five senses to detect everything around her. She could feel that her hands and ankles were chained and she was suspended in a way that she could not touch anything. With her sharpened hearing and sight, she could tell that there was someone several yards in front of her. She pretended to stay unconscious, but the person already knew that she was awake.
"For the infamous Poison Scorpion, it wasn't very difficult to capture you."
"This voice...Tsuna? What's going on?"
Lights turned on and blinded her. She saw herself in a room full of tools designed for the sole purpose of torturing people. Chains dangled from the ceiling and there were bloodstains on the chains, walls, and tools.
"Tsuna! Tell me, what is going on?"
"Well, for starters, you're in one of the enemy Famiglia's soundproof torture chambers. I'm sorry, Bianchi; I didn't want to do this, but I had no choice. You were simply too close to my Reborn."
"I knew that you had something for Reborn. That look in your eyes every time you looked at him..."
"Regardless of what you know, I'm afraid that this is the end."
Tsuna's hand reached towards one of the many tools. Soon, screams resounded through the chambers and blood and body parts were splattered on the walls and floors. The people sleeping in their rooms above the torture chamber couldn't hear a thing.

Tsuna watched Reborn pacing through around his office, trying to figure out what had happened to his magenta-haired lover. Reborn eventually stopped and sat down in a chair, still trying to figure it out. Tsuna looked at a mirror.
"Soon," the reflection mouthed.
Tsuna smirked.
That night, Reborn found himself chained in a dimly lit room.
"Reborn..."
Someone stepped out of the shadows. Reborn's eyes widened.

"What's going on?" he asked, struggling.

Tsuna smirked.
"Struggle all you want. Your coffee was drugged, so now I'll enjoy you thoroughly; we have all night. And after tonight, I'll free you and then do the same thing the next night. You're mine."
Reborn felt an intense pain in his backside.
"Mine."
He screamed.

That…was the most disturbing thing that I've ever written. Anyways, so by the end of the story, Bianchi is dead, Reborn doesn't know who killed her, and Tsuna is insanely in love with his tutor to the point of raping him… Excuse me while I go bang my head against a wall.

To Kururo Saruko (Because I couldn't PM)- I tried to keep them in character but the thing is, this is Dark/Insane! Tsuna after he gets the position of Vongola Decimo. Naturally, he's a lot stronger now. Bianchi and Reborn were both drugged so Tsuna gets a bonus. Bianchi was taken by surprise and couldn't defend herself. Reborn was getting depressed about her dying (they're lovers) so he was also kind of defenseless. Also, at the end, Tsuna didn't inject a drug; he stuck something in Reborn's a** and thrusted it in deeper, so Reborn felt a lot of pain, thus the implied rape. Hope that answered everything ^-^