In Dreams, Truth
"You really are the dark side of the Mafia, aren't you, Xanxus?" Those were the first words Rokudo Mukuro ever said to him, the first time their paths crossed. Not the first time they knew of each other, though, not by far - Mukuro notorious for the Mafia families he'd destroyed, Xanxus infamous for his failed usurping of the Vongola.
From the way Rokudo Mukuro looked at him and the tone of his voice, Xanxus could be sure that Mukuro knew who he was, and hated him for it. Or so he thought - Xanxus had been frozen away while Mukuro was committing his many murders, but he knew the basic story well enough: Rokudo Mukuro loathed the Mafia. Surely he would loathe Xanxus more than anyone, who embodied the cruelest, most vicious aspects of that life.
Xanxus liked that thought. He cared little what most thought of him, but he had to admit a certain fondness for being hated and feared. Fear gave him power, gave him control over the people who felt it, and hate was no less useful.
That was all he thought of Rokudo Mukuro the first time they met: the Mafia criminal, lowest of the low, feared by so many, and surely he must hate Xanxus, no matter how light or pointless his words. Anything else didn't even matter, not Mukuro's power, not the way he won the Ring of Mist from an Arcobaleno so easily.
Why should it matter? Mukuro was only another body in the way of his ultimate goal.
But Xanxus failed, Xanxus lost to Sawada Tsunayoshi, a sad excuse for a Mafia boss who would never be hated or feared, who would no doubt rule with kindness. He'd never be the boss the Vongola needed, but he still won, somehow.
In the wake of that defeat, Xanxus' anger and hatred sustained him, as they always had. His dreams were dark, full of blood and pain and death, and he rejoiced in them because he could do little else.
Then he dreamed of Rokudo Mukuro. The blue-haired boy with the mismatched eyes and strong illusions, stronger even than Mammon - why Xanxus would dream of him, he didn't know. Perhaps because Mukuro had known, had warned him that Tsunayoshi would not be the easy prey he seemed, or perhaps it was simply his unconscious mind at work, providing him with an image to destroy.
And destroy he did. The first night he dreamed of Mukuro was a whirlwind of rage and destruction. He crushed the boy's throat, watched him gasp for breath, broke his legs so he couldn't run, smashed his smile in, beat him bloody and lifeless and empty, and when he was finished Mukuro twisted his blood-red lips into a smile and laughed until Xanxus woke up.
It was less satisfying than most of Xanxus' dreams, but it was just a dream, even if he was in a miserable mood that day.
For some weeks, Mukuro made occasional appearances in his dreams, and Xanxus let his anger fly free. He killed the supposed Mist Guardian in hundreds of different ways, tearing him to pieces or beating him to a pulp or smashing his skull against a wall. It never stuck, even in his dreams, Mukuro never stayed dead. He would laugh or simply smirk at Xanxus, no matter how badly he'd been injured. As if it didn't matter.
Finally, one night, Mukuro ran a hand through his hair, picking out bits of skull and brain matter, and said, "Aren't you tired of this yet?"
Xanxus tore his heart out for that, ripping through his ribcage, but the next time he dreamed of Mukuro he held his rage back. It should have been obvious, should have occurred to him sooner - Mukuro was an illusionist, it wasn't impossible that he should be able to walk through dreams, that these might be something more than products of his aimless anger. It would certainly make sense of why he dreamed of Mukuro of all people.
In that dream they were on a hillside, covered in green grass and flowers, a calm brook flowing nearby. The sun should have shone overhead, but though it was as bright as day, they were surrounded only by gray mist. Xanxus watched Mukuro watch him, measuring the illusionist with his eyes, seeing what he could see.
Mukuro was still young, no more than sixteen. His clothes and strange hairstyle made him look more like a delinquent boy than a multiple murderer, but his eyes - one red and one blue, both cool and merciless even with a smile on his face - showed him for what he was. The cunning eyes of a killer, and Xanxus knew that look well enough, having seen it in his own eyes for years. No doubt Sawada Tsunayoshi would never understand it even if he could see it, but Xanxus did.
Strangely, it relaxed him.
"Why are you bothering me, trash?" he growled, thinking of all those nights when he beat Mukuro, felt that thin body give beneath his fists.
"You're very interesting," Mukuro said. "And very strong." He smiled.
"As if I give a shit what you think of me," Xanxus said. "You just go crawling back to that spineless brat and tell him whatever you can, don't you?"
"What would I tell him?" Mukuro leaned down and picked a blue flower, twirling it between his fingers. "That you dream of death, that you kill me in your dreams?" His smile was a smirk now. "That sometimes you wake up hard because of it?"
It pissed Xanxus off that Mukuro knew about that, because it showed some knowledge of what happened outside of dreams - and how far that extended, Xanxus didn't know. He didn't particularly care about the fact itself, though. So destroying Mukuro got him off, who'd really be surprised by that?
"The worst parts of the Mafia are personified in you," Mukuro said, plucking the petals of the flower off one by one, eyes on Xanxus the whole time. "And yet I can't help feeling like we have some things in common."
"I've got nothing in common with scum like you," Xanxus said, but if he were to be truthful he would have to admit that he felt some of the same thing. Mukuro was the kind of person Xanxus hated, but he was also driven and powerful and full of hate behind that laughing smile. He'd kill without regret or remorse, he'd even get pleasure from it. And someone like this was serving Sawada Tsunayoshi - it was either disgusting or hilarious, Xanxus couldn't decide which.
"That's all right," Mukuro said with a sharp smile. "I'll kill you one day." He said it so lightly and pleasantly that Xanxus had to bare his teeth in a feral grin, answering Mukuro's.
After that, Xanxus dreamed of Rokudo Mukuro on an irritatingly irregular basis. If it had been every night, he'd have hunted Mukuro down and killed him just to get that face out of his dreams. If it had been never again - well, he probably wouldn't have cared at all. But no, the Vongola Mist Guardian could never be as predictable as that.
He would dream of Mukuro every day for a week, and then not at all for months. Twice in a two-week period, then nothing for three weeks, then one night... it was impossible to predict when Mukuro would decide to drop by for one of his little visits, and the most infuriating part was that Xanxus slowly grew certain that Mukuro only did it when he was bored. As if Xanxus were some sort of entertainment for him.
That alone would have made Xanxus intent on destroying Mukuro when next they met. He was no one's entertainment, especially not some cut-rate illusionist who couldn't even get himself out of prison (never mind that Xanxus was intimately acquainted with confinement, and if he had had that kind of escape he probably would have taken it as well).
But he couldn't kill Mukuro, even for him it was impossible to do in dreams. Mukuro just laughed and laughed, let him inflict what damage he liked and then disappeared. There was no point to it, even if it was satisfying, and Mukuro occasionally brought him information, things he could use - locations or weaknesses, things the Varia exploited to destroy their targets. Xanxus couldn't ignore that, though he was never sure if Mukuro did it because he wanted to or because the Sawada boy had told him to. How much of a Vongola dog had Rokudo Mukuro become?
His visits became unsurprising over time, Xanxus even came to anticipate them. Mukuro pissed him off, but in those dreams he could do anything. He could work out his anger, fight with Mukuro, ignore him, even talk somewhat civilly - anything he felt like. It was a distraction from his ridiculous subordinates and a window into what the main Vongola family was doing.
As Tsunayoshi grew older and gained more control over the family, the visits changed. It almost felt like business rather than... well, whatever it had been before (pleasure? boredom?). Xanxus would never bend his knee to Sawada Tsunayoshi, would never accept his position as the head of the Vongola, but in their own way the Varia continued to work for the family, and Mukuro served as some sort of strange, unofficial liaison, passing plans and information and whatever else he felt like.
Other things changed, too. In his prison, Mukuro grew older, and his appearance in the dreams changed as well. No longer a skinny smiling boy, it was really no surprise to either of them when the fighting turned into something more charged, more dangerous. Xanxus cared little for propriety and didn't deny himself pleasure, and it was immensely pleasurable to tangle his fingers in Mukuro's long hair, slam him against a wall (desk, tree, whatever was available), and fuck him hard enough that their movements were slick with blood.
Even outside of dreams, Xanxus was as far from gentle as it was possible to get, and in those dreams with Mukuro anything was possible. He wasn't playing games, and if Mukuro was then that just meant he had a taste for Russian roulette, because if they had done those things in real life, someone would have ended up dead. But Mukuro just laughed, lips curling into a cruel little smirk even when Xanxus' hands were curled around his throat, strong fingers nearly crushing his windpipe, hips moving as he fucked Mukuro harshly.
Xanxus had always found that he broke things far too easily. He liked breaking things, liked the satisfying crunch and the knowledge that he'd ruined something with his own hands. If there was something he couldn't have, he'd rather break it than give it away - that was how it should be. But Mukuro always mended, he always showed up the next time looking pretty and perfect and untouched, no bruises or blood or shattered limbs, no marks where Xanxus' hands had been. He couldn't own Mukuro and he couldn't break him.
He was not inclined to philosophy, but sometimes he thought Mukuro was some strange sort of kindred spirit, taking a twisted satisfaction from the things they did, encouraging Xanxus to even more violence and excess, things no human being could take - but Mukuro could. Even when they weren't fucking, even when they talked business, there was a gleam in Mukuro's eyes when Xanxus spoke of the things the Varia did, the things gentle Sawada surely tried not to even think about.
Mukuro was more suited for the Varia than being one of Sawada's dogs, Xanxus decided, with the deep darkness at his core, the desire for violence and chaos that Xanxus found so familiar. But even the idea of working with him was pointless, because Xanxus knew that Mukuro would never be content as a follower. Such a thing would end in death, either his or Mukuro's or both, and that was why these dreams were so satisfying. They were too alike to ever coexist except in dreams.
It was long years before they met again in the real world, at that last decisive battle with Byakuran. It was strange to see Mukuro in person, and it made the world feel for a moment like one of those bloody dreams that he hadn't had in months, and then they all had other things to think about. But hearing Mukuro's voice, seeing his irritating smirk, made Xanxus anticipate the end of this battle - the moment when, perhaps, he'd be able to see just how much this real Mukuro could take, how much he could bleed and tear and bend before breaking, how true this history between them was.
The real question was which of them would break first.