VERY IMPORTANT EDIT: As of 11/21/2017, this work is discontinued until further notice.

I don't own Katekyo Hitman Reborn.

Beta-ed by: NightmareAx7

TRIUM REGNA, the Three-Realm System

The system encompassing the three worlds of life; Caeleste, Tartarus and Terra. As long as the Lords of Caeleste and Tartarus are present, the balance of the system will never collapse.

CAELESTE, The Paradise of Angels

The first world of the Trium Regna. Caeleste is the world of angels, governed by the King of the Celestial Kingdom. The pure souls of humans are directed here from purgatory, where their good deeds are rewarded. Humans call this world Heaven, the land of paradise, of which their speculations are indeed correct.

TARTARUS, The Domain of Demons

The second world of the Trium Regna. Tartarus is the realm of demons, governed by the Lady of the Tartarean Domain. The tainted souls are directed here where they repent for their sins. Humans call Tartarus Hell, the sea of flames, which is not entirely false.

TERRA, The Land of Humans

The third world of the Trium Regna. Terra is a world largely populated by humans. Only angels and demons approved by their higher-ups are allowed to enter, and lead souls to do good or coax them into evil. Humans call it Earth.

Tsuna sighed, and closed his eyes. He was holding the book given to him as a gift on his 250th birthday. The book was the only one that contained information about the three worlds of the Trium Regna. The only section he just finished reading was the introduction. Deciding to continue, he opened his eyes and read.

-•-

After a while, Tsuna decided to stop reading and placed his orange bookmark on the page, closed the book and returned it to the bookshelf. Tsuna was currently hovering, his wings enveloped by a barrier of invisibility mentioned in the book earlier.

The library had no makeshift footholds, the shelves held together by webs of magic, done by their Lady. The bookshelves covered all the walls and also occupied the middle space, as the library was gigantic. The stairs that led to the quarters of the Pillars were mostly invisible, appearing only when needed.

After he returned the book, he stepped on the wall and used it to propel himself to the stairs. He climbed the stairs and came upon the quarters of the Pillars. Tsuna was the only demon present in the floors above the library. The other pillars were roaming around Tartarus and his Lady was in a meeting with the King of Caeleste.

Tsuna headed to his room and sat down on his bed. He turned his head and looked at the painting of the Tartarean Pillars. He, Sloth, was at the middle, trying to placate Wrath who was bantering with a laughing Envy. Greed had his fist pumped beside Envy. Gluttony was sitting in his chair at Tsuna's other side, eating his favorite grape-flavored treat, with one Lust wiping his mouth. The other Lust was at the side far away from a snarling Pride.

He smiled fondly at the picture, taken on his 200th birthday as Sloth. Although they had different personalities, often clashing with another, they were a perfect team in times of crisis or war.

He loved his friends and respected his Lady and because of that respect, he would never disobey his Lady. Even if his Lady never allowed him to visit Terra, he never disobeyed and sneaked out to visit Terra. On the contrary, the other Pillars had been there a thousand times and still counting. Even the lower-ranked were allowed! So why was he, the leader of the Tartarean Pillars, not allowed to go down to Terra? And why was he allowed to visit Caeleste- "A demon shouldn't be able to go to the paradise of angels anyway!" Tsuna screamed-, but not Terra?

Tsuna assumed it was because his friends requested the Lady to never let Tsuna go down to Terra, because they were overprotective bastards. He suspected that even the Lady was protective- Tsuna was flustered by the thought but dismissed it, little did he know that he was correct- and that's why the Lady was cooperating with his friends.

The brunette sighed. His friends' overprotectiveness was completely unreasonable. Anyone who objected would be given a broken nose, courtesy of his fist. Besides, he was the leader of the Tartarean Pillars, meaning he was strong, proven by the numerous injuries Pride has after they spar. It was impossible for him to be attacked by angels, as there was a truce of some sort that prohibited fighting between angels and demons. Even if he was attacked, most of the angels were no match for him. Archangels did not count as they will never disobey their King. Only a small population of the Hunters were able to match him, and he trusted his ability to escape if ever he was attacked.

He yawned, and noticed that his Sin had decided to mess with him. This was one of the times he hated being Sloth, his Sin was making him feel sleepy even though he woke up just 5 hours ago. He sighed and fell back onto his bed.

Tsuna was lying down on his bed when a strange feeling hit him. It was like he was being pulled, but he didn't know where to. Deciding to let things take their course, he allowed himself to be pulled, and closed his eyes as he went through a vortex.

When Tsuna landed, what greeted him was the sight of an office. And a blonde human staring at him from where he was standing near his desk, holding a flamethrower aimed at the stacks of paperwork on said desk.

The blonde was wearing a black suit jacket over a white dress shirt and black tie, along with black slacks. Not very different to the brunette's clothes.

Tsuna was wearing an orange button-down shirt that had a pin on the collar with a black tie, coupled with black pants. The pin had a black base shaped like a flame with a blue moon in the center, which changed according to the phases of the moon. The black flame base was flanked by two golden pillars at each side.

Tsuna stared at the human, and the blonde stared back at him. "Umm… What are you doing…?" Tsuna hesitantly questioned.

The blonde blinked at him, then put down the flamethrower on a table near his desk. "Nothing. And you? How did you get in here? I didn't even hear the door open." The human asked.

Wait… Human…?

Tsuna's eyes widened. "E-excuse me! Are you a human?!" Tsuna questioned, grabbing the man's shoulders. The blonde looked at him incredulously, but answered anyway. "Y-yes, I am human…" Tsuna shook his shoulders, "A-and you're not dead yet?" The blonde looked at him, offended, and swatted Tsuna's hands away from him. "I'm obviously alive." he said.

Tsuna's eyes lit up in realization and soon, he was shaking, making the blonde worried for him. "Hey, are you alright?" the blonde asked.

Unknown to the blonde, Tsuna's mind was full at the sudden realization of the situation. If a human was before him, alive and kicking… Then that means…

"This is Terra?!" Tsuna shouted, surprising the blonde.

Okay, this is just the prologue. I'll get to writing the 1st chapter when I have time, namely weekends~~ Thanks for reading and please wait for the next chapter~! See ya!