A/N: This is what happens when I'm working on a story and revisiting a book series I haven't read in a while. A possible What If? scenario for the Ghost of a Chance universe. And yes, the pop culture references in Daniel X really were that cringy. It basically wrote itself.
Edit: Took a quick look at the Dangerous Days of Daniel X section, there weren't that many stories. So I decided to go back and add more details about the characters from that series.
Disclaimer: I don't own Katekyo Hitman Reborn! or the Daniel X series. I have the DS game though, does that count?
Tsuna, the Alien Hunter
When Daniel headed to Namimori, Japan to defeat one of the numbers he wasn't expecting to play babysitter. Daniel's parents had been from Alpar Nok, a planet that was once responsible for policing the galaxy. They had been assigned to Earth to track down criminals that decided to house themselves on the planet. When he was only three, a criminal known as The Prayer had broken into his home and murdered his parents. It was looking for The List, a computer that had information on all the criminals hiding on Earth. Now a teenager, he tracked down these criminals and eliminated them.
There were two siblings cornered by a group of suit wearing man, guns being pointed at the boy. His sister, a girl that looked like she was made of energy, placed herself in front of him. "Leave big brother alone!" Shizuka snarled, pushing the men back with her energy. "Why don't you guys try picking on someone your own size." Daniel says, not surprised when the guns were pointed at him. At least these guns seemed to be of Earth origin. Daniel easily dodged the barrage of bullets, quickly disposing of them with his fists.
Tsunayoshi watched Daniel approach them fearfully while his sister stood in front of him protectively. Daniel sighed, he just couldn't resist being a hero. "Hey, relax kids. I'm not going to hurt you." Tsuna and Shizuka looked stunned. "Y-You can see her?" "You can see me?" They asked simultaneously. "I'm not exactly a good example of normal myself." He says, Shizuka raised an eyebrow. "We could guess that by how you took those morons out." She says bluntly. "Aren't you a little young to be so cynical?" Daniel asks. "Aren't you a little old to be quoting cartoons?" Shizuka retorts.
Daniel had taken a quick look into one of the attacker's minds, his brow furrowing at what he found. Apparently he had rescued the two children of a high ranking mafia man. One of them had some sort of seal on them that was screwing with their brain and motor functions, the other didn't have a body at all. "How about I take you kids home. I'm sure your parents are worried." This made Shizuka scoff and Tsuna shot his sister a worried look. "I don't know." Tsuna says warily. "Oh come on, it isn't like I'm an ax murderer or anything."
If Daniel didn't know any better, he would have thought that Nana Sawada was an incomplete projection that someone had created. Or maybe a robot. While she did all the functions expected of a human, her eyes were eerily devoid of life. "Thank you for bringing Tsuna home, he tends to wander around and hurt himself when he's not supervised." She says, Shizuka ignored the woman and headed upstairs. Tsuna trailed behind her, his hair shadowing his eyes. Daniel might have had his real family for only three years, but everything about this place screamed it wasn't an ideal environment for children.
XoXoXoXoXo
"This place isn't safe Tsuna. What if more of those guys come and try to take you away?" Shizuka asks, frustrated that she couldn't do anything. The most that she could manage was nudging objects or turning pages, and making herself solid only lasted a couple of minutes. And pushing people away was draining. They were sitting ducks. "Maybe we should call the police." Tsuna suggests, Shizuka shot him a look. "Like when you tried to tell them about your bullies? Not even Mama believed you." Shizuka says.
"Looks like you two were not dealt a good hand." Tsuna gave a startled scream when Daniel appeared in his doorway. "We thought you left after your whole good Samaritan act." Shizuka says, going into one of Tsuna's bags for a book. Daniel didn't know anything about the development of a normal child's mind, but he was positive that they were way too young to be reading Frankenstein. Completely in English if the cover was any indication.
"If I just left you two here, it would be like a stubborn pop up ad refusing to exit out." Daniel says, Tsuna and Shizuka deadpanned. "Is that a cooping mechanism for something?" Shizuka asks. "Because if you were trying to get us to laugh you failed." Tsuna added. "Yikes, tough crowd. I was going to get that seal off your brother." He says nonchalantly, the siblings looked stunned. "You can do that?" Tsuna asks timidly, Shizuka glared at the teen. "You better be able to deliver on that promise or I'll haunt you." Shizuka threatens.
When Daniel prodded at the seal with his own power, he was surprised when something latched onto it. It seemed Tsuna was unconsciously chipping away at the seal with his own energy, all it needed was a little hand to speed up the process. When it was completely removed, Shizuka and Daniel were both blown back. Tsuna's eyes were now amber and he appeared to have fire, similar to what his sister was made of. "My head doesn't feel foggy anymore." Tsuna says in awe, flexing his hands. It was as if he was seeing them for the very first time.
"I suppose you aren't too bad." Shizuka says begrudgingly. It still wouldn't solve the current assassination problem they were having. Luckily Daniel had always wanted some sidekicks. "How would you like to help me take down an evil alien?" Daniel asks. Shizuka and Tsuna both had a silent exchange, one of those weird twin things that Daniel still thought was creepy. Shizuka smiled, for once not glaring at the teen. "Why not? Sounds like it could be fun. It's better than staying here." She says with a shrug.
"But what about Mom?" Tsuna asks, Daniel smirked. "That shouldn't be a problem." He says, making an exact duplicate of Tsuna. The Sawada's jaws dropped. "You can do that too?" Shizuka asks, looking put out. "I can teach you if you want. You're already made of energy, you just need to learn to control it. Anymore questions, comments or concerns?" He asks. "Nope, we're good. Lead the way."
XoXoXoXoXo
Shizuka and Tsunayoshi were stunned when a group of teens suddenly popped into existence. A girl with her hair in french braids squealed, scooping the children into her arms. "Aw! They're so cute!" Emma gushed, Tsuna was struggling to breathe and Shizuka scowled. "You might want to let off on the affection sis, they need air." Joe, Emma's older brother, says in amusement. The nature loving girl reluctantly released the children and pouted. "Dan, you sure taking these kids in is a good idea?" William, or Willy, asks.
"It's better than leaving them at the mercy of those assassins. And I doubt that their mom would have been much help." Daniel states. Shizuka crossed her arms. "She never picked up on Tsuna getting bullied, there was no chance of her being able to notice professional killers." She says bitterly. "Well, at least the police will be on the look out for any more suspicious people in town." Tsuna says optimistically. Instead of the police station, the siblings suggested leaving the tied up criminals on the door step of the Hibari home. Everyone in Namimori knew that if you wanted anything done, you usually went through the Hibari clan. There was also the fact that one of the sons could actually see Shizuka and she wanted to say goodbye.
"Alright kids, these are my friends Emma, Joe, Willy and Dana. They usually pop up when I need company." Daniel explains. Shizuka and Tsuna fidgeted nervously. "A-Are the ghosts like me?" Shizuka asks hesitantly. Dana bent down and patted the girl on the head. "We're not truly dead, we live on in Daniel's memories. But you could say we're a lot alike." The blonde says, Shizuka looked up at the teen in awe. "Then I can be solid like you guys?" She asks, Joe laughed. "Kid, being a ghost is less complicated." Shizuka huffed, glaring at the teen.
XoXoXoXoXo
Seven years later Reborn would arrive in Namimori, realizing the Dame-Tsuna that he was dealing with was nothing but an elaborate illusion. He swore the next time he saw Iemitsu, he was going to kill the man. Shizuka and Tsuna watched the hitman fume on Daniel's laptop. "I told you installing that camera the last time we visited home would be worth it." Shizuka snickered, blue eyes glinting with mischief. She had eventually stabilized her energy to the point that she could pass as a normal human, with blonde hair and blue eyes. Daniel was still convinced she'd gotten the idea for her human form from Dana.
Tsuna had spiky brown hair and his eyes were usually amber instead of their natural brown. In their profession, they needed to be on guard at all times. It still blew Daniel's mind that he somehow became a parental figure to these two kids. He refused to call himself a mentor, did he look like he wanted an agonizing death? He was not going to be part of the dead teacher trope. "Compared to all the insanity we've been through? I think a mafia tutor would be normal in comparison." Tsuna says bluntly.
"I don't mind going solo for awhile. Even I went to high school as a teen." Daniel says, not mentioning the fact that he'd been kidnapped by Ergent Seth when the alien disguised himself as a cute high school girl. Not one of his proudest moments. "It would be middle school in Japan. Tsuna wouldn't be a problem but I don't have a background." Shizuka says irritably, Daniel grinned. "No problem, we can just call up that guy we met in Italy and make up a cover story." Shamal did owe them one after all.
Shizuka was already packing what little belongings they had, they moved around so much they only carried the essentials. Joe materialized behind Daniel, chuckling. "The baby birds are finally leaving the nest. Don't worry Danny, we'll keep you from being lonely." Joe teased. "Shut it Joe." Daniel says, wondering what he was unleashing on the mafia world. Who was he kidding, he knew exactly what he was doing. There was no way that the siblings were going to roll over and do whatever their father wanted. He was going to sit back and watch as they caused their own brand of chaos on Earth.