converse, n, singular:
1. a situation, object, or statement that is the reverse of another, or that corresponds to it but with certain terms transposed.
2. a theorem whose hypothesis and conclusion are the conclusion and hypothesis of another.

Kenpachi Zaraki was a beast. But he was hardly a fool.

After all, ferocity and bloodshed are, without a doubt, necessary in achieving strength as much as glory; his need to fight and his desire to wound, maim and slaughter in the heat of battle are a testament to the devotion of his quest. And although foolishly brazen, the sheer power hidden behind his eyepatch and within his blade have shown him to be formidable indeed. So yes, Mayuri deduces, Kenpachi Zaraki is a beast, but he is also a warrior- and what are warriors but harbingers of destruction and glory through altercation?

Somehow, underneath that external barbarism, Zaraki has a drive that Kurotsuchi finds as infuriating as he does admirable. Not many can match his own strength in will, the passion for a calling that all creatures are lost without. But regardless of Zaraki's evident willpower, his character has always been little more than a revolting brute. He charges into the fray of a skirmish blindly, swinging his blade like a madman and nearly taking off his own head in the process. And while Mayuri cannot hide the twinge of amusement that accompanies the thought of Zaraki accidentally maiming himself by hurling his body onto his own blade, cleaning up the mess that such an incident would leave behind is an… undesirable thought, at best.

As if he has time to waste with taking care of Eleventh Division's misfortunes.

As if he has the mind to care about something as insignificant as the rage that Zaraki seems to harbor for him, ever since that disastrous battle with the Soul King's left hand.

Mayuri can't even remember the creature's name, now; the samples he'd longed to collect were eviscerated along with the rest of the Hand's form, just as Nemu herself had been… eviscerated. Strange how he still finds his memories tending toward her, as though she had been something important, something…

Perfect? The voice in his head questions, and Mayuri cannot help the laughter that spills from his lips, as his hands press to his face and he cackles, only becoming more the picture of insanity that many already considered him to be.

"I knew you'd lost it, you son of a bitch," Zaraki spits out in a voice somewhere between haughty and callous. The words twist themselves twice-over about his brain, compressing the organ in a manner akin to a length of string, piercing him before he manages to file the phrase away, and Kurotsuchi does nothing more than shake his head. His piercing eyes remain wide, lips pursed as he turns his attention back to his laboratory table- the only thing in this room which truly held any use for the time being.

"Look at me, Kurotsuchi, damn you-"

"Quit your prattling, won't you? I've had to listen to enough tantrums in one day to rival the past five years, and your incessant chatter is making it rather difficult to think." The Twelfth Division captain dangles a vial between his fingers, letting it hang in front of his face for a moment as he watches the red liquid inside slosh backandforth backandforth.

"Listen, you lunatic," and the sample is slipping, the scientist's bony, pale hand grasping aimlessly for the vial as it falls, slower and slower, and then shatters against the floor at his feet. And there's something locked around his wrist, heavy and tense and wrapped with bandages, and too late Kurotsuchi notices Zaraki's hand, keeping his own in place, restraining him- the nerve of this fool, this deplorable swine!

Kill him, something in Mayuri's head says, he's the reason that your most magnificent creation was destroyed, your reputation slandered, your laboratory in shambles. If the damned philistine hadn't decided that he was capable of winning against the Wandenreich alone, you would be in possession of Nemuri Nanagou AND Pernida Parnkgjas-!

"Unhand me this instant, Zaraki!" He hisses instead, turning his head at an unnatural angle until his neck is strained, but Kenpachi's face is directly in his line of sight. And Zaraki nearly releases his grip, nearly does what he's been asked, until he seems to think better of it, and he smirks. His presence is everywhere, invading Mayuri's space in the way only a failed experiment is able to do, and as he leans in closer, Kurotsuchi finds his shoulders tensing automatically, his body halting in its motions to escape the barbarian's hold. He's surprised, and isn't that something, at this point in his career?

"You're vulnerable," the man breathes, and the heat of his words can be felt against Mayuri's skin, his chuckle filling the entirety of the room with noise. "Because you are losing it, aren't you? You finally snapped- aren't even saying anything in your defense. Heh. What a shame."

Mayuri's hand slams against the table at his back, and he wonders how he's been standing without his notice; papers crumple under his fingertips, and his teeth clench together, blood filling his mouth from the place where he's bitten his tongue. He can't help thinking Zaraki would look lovely in a specimen jar, now, all torn up into bits, with each organ properly labelled. Incapable of defiance. Incapable of causing him confusion.

"You know," Kenpachi says, close enough to hit him, close enough to kill him, "this is how I felt when you turned your blade on me. Weak."

Weak, was it? What a trivial term, especially when used by a lesser mind like Zaraki.

Mayuri's mouth opens, his throat parched, voice cracking in such an undignified manner that he doesn't have the capacity to catch the useless word before it spills out of him.

"Yes."

It's short, concise, acquiescent. The sort of response Nemu would give under direction, the only word that ever mattered when it came to her- of course, she'd developed her own cognition, superseded his own programming. Even now he was hardly sure what to think of that- had she surpassed him?

Had he been forced down another peg, squandered under the reputation of Kisuke Urahara, the brilliant, ingenius Captain of the Twelfth Division, yet again?

Zaraki appears to be as startled by the response as Kurotsuchi himself, his eyes vacant even as they keep focus on Mayuri's face, until Mayuri bats his hand away and turns, refusing to look at this beast, this- man, who is more like him than he ever wishes to admit.

"If that's all, Zaraki, won't you leave me be already? I have no desire to hear the asinine cursing and incoherent ramblings of a brute like yourself. As you know, I'm a very busy person."

Busy, or weak? Vulnerable? Jealous? Nauseatingly emotive? A worthless, dysfunctional, broken toy just like one of your failed creations?

"Heh," Zaraki scoffs. "Then at least answer me this."

"If I must." Mayuri mutters, reaching for a carelessly discarded scalpel.

"Why the hell are you crying?"

And… oh. Oh, is this what it feels like, to have tears in his eyes, to be so pathetically human, so impuissant that the very idea of it causes Mayuri shame? How amusing, he decides, that he'd not noticed before, the spots across his vision or the scorching liquid that trails over his cheeks, leaving tear tracks through his black and white makeup.

Still, it's disturbing enough that he's devolved to a behavior usually left for primitive test subjects. He will have to fix this, of course; seal the ducts over and cauterize the wound after he gouges them out, temporarily remove his eyes so he can add a lining to the sockets… there are options, as there always will be for those with the mind to look for them.

Mayuri's eye twitches, his brow pinching tight when he finally levels Zaraki with a scowl, unamused.

"I am not…"

- weak, pathetic, trivial, childish, insecure, egomaniacal, underdeveloped, inane, irreverent-

"... anything like the rest of you troglodytes. How dare you insinuate that I share any similarities with…"

You.

But that final word never passes the scientist's painted lips. How could it, when he's cornered, when he's confused, trapped in this melancholic headspace like a lab rat in a cage, waiting in petrified terror and ignorant of its fate? How could it when Zaraki has made him into the fool? Him, Mayuri Kurotsuchi, him, the seraphic?

"You're even crazier than I am," Kenpachi laughs, then, a ghastly, horrendous sound, loud enough to purge all of the silence within what remains of Kurotsuchi's (not Urahara's, never again Urahara's) lab.

Mayuri grabs him by the front of his shihakusho, twists his fingers into the fabric of his hakama and his haori until the nails are nearly splitting with the pressure on his own nerves-

(Nerves! his brain cries, all the endings exposed, your nerves, exposed and all your work undone, so vulnerable to them vulnerable to him get him away get him awayNOW-!)

And he can't breathe. He can't breathe, because his lips are smashed against Zaraki's, how repulsive, how lowly, but Kurotsuchi can't help himself, he wants to tear Zaraki open and devour him and wash his hands in the blood of his fellow pariah as he reaches deep inside his vivisected stomach and-!

His hand is on Zaraki's shoulder and he's shoving him away, smacking him across the face as soon as Mayuri has the mind to realize exactly what he's done. But Zaraki is Zaraki, and he refuses to relent, refuses to do anything more than seize Mayuri about the waist and crush their faces together again, tonguing his mouth open and sliding hands around the globes of the scientist's ass with a forceful dominance that isn't entirely unappealing.

"You're disgusting, Mayuri." Kenpachi voices as they part for air, as the other's bony hand and vicious nails claw into his skin. But Kurotsuchi doesn't care, never has, because he knows exactly how odious he is, has known for far too long. "At the end of your rope and throwing yourself at a barbarian, eh? How the tables have turned."

"'Throwing myself at you.' Don't flatter yourself, Zaraki. I've only allowed you this service because I want something to tear apart. Fortunately you seem to be a rather accommodating specimen. I've seen how you fight. You'd toss yourself onto your enemy's blade a thousand times if you could. And that is a rather revolting trait, wouldn't you say? The desire to bleed and break yourself open for another's amusement?"

"Then I'd think it makes sense that I've got a sadist desperate for me to fuck him."

"Vulgar," Mayuri shoves him aside, the long nail on his third finger teasing under Kenpachi's chin, pressing just over his throat and the bump of his Adam's apple. He wonders how easy it would be to slit Kenpachi's swollen trachea open- just like this, when Zaraki is within the reach of his arm, when his arrogance is nearly overwhelming the air with its stench...

Kurotsuchi averts his eyes. Frowns. And then snatches his own hand back, turning away from the Eleventh Division captain altogether.

Zaraki does not try to recapture his attention. But neither does he leave; he stands in the middle of the room like a well, the weight of his reiatsu clinging to the walls and seeping into the floor and Mayuri's own veins, over his spine and his head and every place the bastard had touched before. Mayuri's teeth clench. Kenpachi speaks before he can.

"You know... I don't hate you, Kurotsuchi," he grins, capricious, maniacal. "You're a sick bastard, but..." he trails off, hand braced on the hilt of his own zanpakutou, spinning on his heel to make for the door, only casting a glance behind him once the light of the Seireitei outside has permeated the pitch of the dingy laboratory.

"... I could never hate anything so pitiful."

(I could never hate anything as broken as myself.)

A/N: originally posted on Ao3; tossing it over here in case anyone else has interest. i'm rarepair trash. this is meant to canonically happen post-TYBW arc, which i'm super excited to see animated.