Leo's barely conscious when the creature stops dragging him, blood dripping from where his scales were ripped off as it dragged him through rough stone corridors and squeezing pipes. His hands are calloused and bloody, still throbbing after he dragged his blades along the walls in a desperate attempt to pull himself free, or at least show his brothers how to find him.
He doesn't know if they will--he doesn't know if they're even alive. He doesn't know where his blades are, either, although he hopes they're scattered somewhere around here.
Wherever here is. It's a part of the sewers they haven't explored very much, with moss-slick walls that would be a bitch to climb even if it weren't for the tentacles slithering over them, watching for any escape attempt. More tentacles loom overheard, rising up out of the place too dark for him to make out.
There's some kind of brazier strung up nearby, painting the room in gently dancing flame. People have been here. "Hello?" Leo calls out, hugging himself against the chill. It's impossible to avoid the looming, unmistakable sense of being watched. 
He darts back as more tentacles slither out of the darkness, curling around the ground. Leo swallows, his mouth suddenly dry. "C-can you hear me?" he asks, trying not to think of how ridiculous it is to be sharing a conversation with a bunch of tentacles.
But there are plenty of people who would think it ridiculous to be in a conversation with something like him, Leo reminds himself, so he keeps going. "My name's Hamato Leonardo," he says, trying to sound as reassuring as possible. "My brothers and I, we mean you no harm. We didn't intend to scare you--"
The tentacles around him shudder with some sort of quaking force, the vibrations sending Leo swaying on his feet. Laughter , he realizes suddenly, a cold spike of fear filling his gut. It's laughing. 
A cluster of tentacles abruptly start shaking and swoop towards him. Leo tries to dodge, but that just puts him into the path of another tentacle that swipes out from under him. They wrap around his limbs and waist, the cold burning into Leo's flesh as he's hoisted into the air.
"Fuck!" He reaches for a knife in his wrappings, but it barely scratches the thing before it's knocked away. Another tentacle comes flying out of the dark and cracks across his face in brutal punishment, leaving his head ringing. More tentacles wrap around his fingers, binding him until they'd cut off the circulation if they got any tighter.
The tentacles flex and Leo feels himself being spread out, exposed like a butterfly pinned on a board. He squirms, ugly memories flickering at the back of his head. No matter how hard he tries, he can't make out anything when he squints into the darkness, just the flicker of more tentacles.
"Who are you?" he rasps. His voice is shaking a little, but fuck it, he thinks he's permitted. " What are you? What do you want?"
Silence. A tentacle falls down out of the dark and brushes down his face. Leo clamps his lips shut, heart thudding, but it easily shoves through, and oh fuck it's in his mouth. He expects it to be damp and cold, but instead it's so terribly warm, and sickeningly sweet, albeit tinged with the faintest hinge of blood.
He thrashes, sucking in panicked breaths through his nose. He can feel it pushing deeper, deeper, only instead of going down his throat it seems to be pushing at the roof of his mouth, towards his skull. It's going to fucking kill him, he's going to--
Then something, somewhere changes. It shudders in an odd, manner perhaps with concentration or satisfaction, and Leo almost hears the door opening somewhere in the recesses of his mind.
He knows, then, with the cold familiarity of one who has experienced such things before, that he is no longer alone in his own head.
Its presence is sickeningly reminiscent of Kitsune, but it is nothing alike. Kitsune prefers to creep, sly and precise, picking along the edges of the consciousness and teasing at its corners, searching for something of use. This is a vast, cold intelligence that regards Leo in his entirety, processing him as easily and quickly as a page in a book.
Leo sucks in a breath as it feels it turn everything about him: his identity, his memories, his hopes and fears and dreams, the secret shames and traumas that he carries under his skin. He wonders if this is what humans feel like when they're stripped naked before the eyes of strangers, helpless and exposed. It terrifies him.
Hmm, the creature in a voice as deep as the folds of the cosmos, as cold and icy as the distance between stars. Leo thinks he can hear a distant scream at its edges, one that might fracture his mind if he focused on it for too long. You will do.
It pulls out of him abruptly and Leo slumps forward with a gasp, shuddering. A tentacle wraps around his chin and lifts it, turning his head from side to side.
Yes, very nice, it says approvingly. It lets go of Leo's chin and slides down his shoulders, his chest, petting and rubbing at his body in an oddly proprietary way that makes something cold twist in his stomach.
"Who....?" he rasps.
The ones who have summoned me call me Shub-Niggurath, it says. It is as good a name as any other. I have never understood this dimensions' fascination with labels.
"The ones who have summoned you?" Leo lifts his head, scanning the shadows, but he can't see anything.
One of the tentacle waves in a dismissive gesture. They do not matter. A pack of fools who have brought me here in hopes of seeing their world destroyed.
"Is that what you're going to do?" Leo asks, swallowing hard.
No. I have no interest in this world. Besides, the rift is unstable--if I brought too much of myself through, I would risk being damaged when it closes. Leo starts to sag in relief, only to stiffen as he feels those tentacles brush up against his thighs, carefully sliding around the curve of his hip.
"What are you doing?" he asks, desperately squinting into the dark. "What do you--"
Do you truly not know? it asks, sounding genuinely curious. I thought you were experienced in these matters.
Leo stops breathing. The tentacle on his hip tightens like Shredder's fingers. Like Kistune's. Like anyone who Shredder wanted him to be with during his time in the Foot Clan.
"No," he begs, shaking his head wildly. "No, no, no no no--"
What is the matter? A tentacle rubs his shell soothingly, in a mockery of comfort, and it takes everything Leo is not to be sick then and there. I know you are small, but I am careful. I will not injure you.
"Why?" He tries, muscles straining, to close his legs, but the tentacles hold on so tightly he knows there will be bruises there tomorrow. If he lives long enough to see tomorrow. If he's sane when tomorrow comes.
They promised me something new, it says. And I like to sample new things. Is it such a crime to want to indulge, once in a great while? Leo clamps his tail over his hole, even though it knows it won't do any good. A tentacle slips under the curve of his shell, carefully feeling the curve of his bottom.
This can't be happening. This is stuff from those weird TV shows Mikey likes, it doesn't happen in real life. It's just a story, like...like witches, and mutants, and reincarnation.
Fuck.
You should be honored, it says. Very few have been graced with my attention, and fewer still in this manner.
"Please," he begs, shaking his head wildly. He feels sick, helpless at being reduced to begging, but he can't go through with this. God, he hasn't been able to so much as jerk off since the spell broke and he realized what had been done to him. "I can't. Not again." Not when he knows exactly what's happening to him this time.
But you have been very well trained. It gives an approving hum. You can service me quite ably. And besides, would you rather it be one of your brothers, who still have innocence left to lose?
The idea hits him like a gut punch. "I don't want it to be any of this!" Leo cries, thrashing like the worm on a hook he knows he is.
Mother, he begs silently. Mother, help me... 
There is no use in calling for her, the creature says, splitting through his thoughts. The tentacle slips under his tail, wrapping up and lifting it away, touching him gently up and down his length. Leo shudders, part with terror and part with terrible force pleasure.
She would not be able to help you if she came. Another tentacle brushes along his hole, soft and teasing. He can feel some kind of cool, wet substance starting to flow at its tip. Would you prefer for her to witness this?
It pushes up against his hole, humming approvingly to itself. Very nice. You remain quite tender. Nausea bubbles in Leo's throat. I want to get a better look.
And then the tentacles jerk, abruptly yanking him into a horizontal position. Leo gasps, blood rushing to his head as he looks up at the still-flickering brazier. His legs are yanked wide, so wide he's scared they'll be ripped off his body, up in the air like a gynecological exam.
He trembles, humiliation burning through him as he realizes how he must look. "Don't...." There are hot tears in his eyes.
Hush, little one. It's brushing the goddamn tears from his face now, patting him on the head like a fond relation. You will enjoy yourself.
"That just makes it worse," Leo grits out.
If you say so. The cold, slick substance is being rubbed into his hole, massaged into the flesh. You are quite odd, little one. But I like odd things.
Leo forces himself to look at where he thinks its eyes might be. "If you do this," he says, steadying his voice as best he can. "My brothers and I will kill you."
You will not. The tip slips inside him and Leo screams, less out of pain than from the all-too familiar sensation of being stretched. You may escape, yes, but you will not kill me. And are you planning to tell them what I have done? I think you are more likely to pretend it never happened, the way you do with all your shame.
The tentacle continues to nudge inside him, exuding more slickness as it wriggles back and forth. It's smaller than some of the others, but it still burns, especially since it's been so long. Leo whimpers.
It is all right. The words are louder now, echoing inside his head, and the distant screams even harder to bear. I know, and I understand. I do not care that you have been used.
"If you understood..." The tears keep trickling down his cheeks, hard as he tries to blink them away. "You wouldn't do this."
Perhaps. It brushes something inside him and Leo cries out. But I do not think it will be as terrible as you claim.
He wants to protest that it will, of course it will, but it keeps pushing up again that dreadful little spot and Leo is too busy gasping and groaning to say anything coherent. A churr spills, out then another, hard as he tries to choke them down.
That's it, he hears Saki at the back of his ear. Moan for me, my little whore. Leo wants to run and hide, to curl up in some dark corner and never come out. But he can't run, and even if he is good there is nowhere to escape from the things in his head.
Pay him no mind, the creature says, wiggling about a bit more. It takes Leo a second to realize he's talking about the memories, and he wants to gag on the fresh layer of violation. Kitsune was cruel, but at least she was subtle. I will show you things he never dreamed of.
It carefully pulls the tentacle out of him and moves to his plastron. To his horror, Leo can feel it brushing along his slit, tracing the faint bulge growing there.
See? It sounds triumphant. All will be well.
"No it's fucking--"
But it's sick of his protests, or maybe it just doesn't care, because a tentacle is swooping into Leo's mouth again. This time it plunges down his throat and he gurgles frantically, shaking his head even though he knows it's no use.
Do not bite me, little one. It warns. I am perfectly willing to knock out your teeth if need be. Leo believes it.
Don't throw up, Leo begs himself. He doubts this thing would care if he choked on his vomit. He tries to remember what Saki taught me about managing his gag reflex, tilting his head back as far as he can and relaxing his throat to the best of his ability.
He squirms, trying to pull away, and that's when it rams him from the other end. It's big, bigger than Saki or anyone Leo's ever taken before, filling him in a way that's perfect and terrible. It wiggles and flexes gently as it slowly pushes deeper, so that his hips rock from side to side as if he's somehow participating in this, enjoying it.
It's too much, too much. Leo can feel himself start to check out, to drift away, and welcomes that feeling. He can feel himself start to slip out of his body, to let someone else play the tortured puppet for a while.
None of that. It reaches into his mind and tugs. He's dragged firmly back into his own body, the few exits calmly sealed off. Leo lets out a sob around the tentacle.
There now. It pushes against that spot in his ass again and it's even worse (better) than before. That wasn't so bad, was it?
It hurts, Leo thinks.
Only a little. It's true, shameful as it is to admit. You feel so good, little one. The tentacles begin to thrust, so that one's always pushing in while the other pushes out, steadily rocking back and forth. I'm glad you're enjoying yourself.
I'm not-- It makes a particular hard thrust and Leo churrs around the tentacle, tail wagging. He can feel the bulge in his plastron growing bigger--keeping it in hurts too much. He'd never tried to resist before when Shredder had him.
You are only making things harder by denying it, the monster chides.
It's just a reaction, Leo insists, flashing back to the sites he'd looked up, the ones that had offered him a bit of comfort on the worst nights. It doesn't mean anything. 
The flesh is the only thing that ever truly matters, child. The tentacles pick up their pace, the one in his ass flexing even harder. Now stop your whining and let me see you. You do not want me to grow impatient. There are more tentacle tips tugging at the edges of his hole, lightly tugging on the quivering rim.
He doesn't have a choice, or at least that's what he tells himself. But there's no explaining away the blessed relief Leo feels when he lets himself drop down, or the fresh swirl of pleasure as several tentacles scoop it up, flowing over its surface.
What a charming little toy, it says, stroking Leo's prostrate thoughtfully. It has not received as much use as the rest of you, has it?
Leo winces. It's true. Even Kitsune had preferred he use his mouth most nights.
I will have to change that. It wraps around his cock like a sleeve, like a warm mouth, covering him all the way up to the--
"Mmmm!" It's the only sound Leo can make when it slides into his cock slit, a shock and pain and terror and yes, pleasure.
This has never happened to you before, it says, sounding pleased with itself. I am enjoying something new tonight; I thought it would be only proper to return the favor.
You can't, Leo thinks frantically as the tentacle pushes up his slit. It won't fit! 
You underestimate yourself. The tentacle in his stretches and wriggles with obvious pleasure, wagging his cock back and forth. Then it pushes in at the same time as the one in his ass, while the one in his mouth pulls out just enough that Leo's next scream rings loud and clear.
Such pretty noises. It shoves back down his throat and Leo chokes, light flashing behind his eyes. But I think I like it when you scream around me even more.
It sets a punishing pace, jerking him about like a rag doll as it jams itself in and in and in. The tentacles in his ass and cock seem to be expanding, growing thicker and longer every thrust.
And yet somehow it feels so much like the Foot Clan; the tentacles turn into hands gripping his wrists, into the Shredder's cock or that of the Foot's allies thrusting away inside him. Past and present pile up on each, sinking into his lungs, choking him.
Maybe he never left, not really. Maybe this is his punishment for thinking he could. 
It groans, and the vibrations rip through Leo's entire body. His cock doesn't seem to mind, but the rest of him feels like it's going to shake apart, and he thinks he might welcome it.
I hate you. He grabs the shreds of hate drifting through his boiling, seizing brain and does his best to push them through the connection, to hurt it however he can. I hate you so much. 
Hate me if you like, but that does not mean you do not need this. The one in his ass curls in on itself and Leo thinks he might pass out, from the pleasure or pain he does not. You were exquisitely broken before I found you, perhaps even before he did.
Memories of his mother's bloodied corpse flash through Leo's head, of Slash's blood dripping down his sword. He remembers how eagerly he let himself be turned into a whore back when he was Saki's slave.
And even now, when he knows that he doesn't want what's going on, his body doesn't seem to carry. Leo can feel himself arching and churring and pushing back into the tentacles, heedless of everything except how very good it feels.
Made for this. The words swirl in his head, and he can't tell if they're Shredder's, Shub-Niggurath's, or his own. Made to be ruined .
He wants to deny it (what else can he do?) but then he feels himself coming, spasming painfully around the tentacle in his cock, and his rational processes crumble. The creature moans again, louder, so loud that Leo thinks his ribs might crack under the pressure.
Oh, little one. It's lapping at the fluids dribbling out of his cock, the drool and tears dripping down his face. You taste like stardust and the blood of angels. It starts fucking him again, harder than before, as if it's losing control of itself.Swirls of energy buzz down his tentacles and Leo's dragged over the edge before too long.
And it. Keeps. Going. Shredder had inhuman stamina, but this was never human at all, and it's thrusts seem to only get more vigorous every time it makes Leo spatter himself with more filth.
By the fourth or fifth one, he's sobbing, really bawling like a child. The pleasure feels like fire now, and Leo's terrified that his edges are going to break down into a blackened, smoking ruin. His mind is a confused mash of please and stop and no more, the words twisting in on each other.
Would you like to stop? it asks. I can go for hours, you know. Leo gags. But things are much easier if I have a kind soul to help me along.
It means...well, Leo's already been ruined, hasn't he? What's one more dishonor? At least then he can be over, and he'll have a chance to somehow glue the broken pieces of himself back together.
He starts shoving himself against the tentacles with a grunt of effort, snapping his hips as best he can in midair. And he starts sucking on the one in his mouth, lapping at it with his tongue the way he knows Saki loves.
Oooooh, good boy. The buzzing gets worse, until Leo's worried about getting scorch marks on his ask. Won't that be hard to explain, he thinks hysterically. So good to me, little one.
When it comes, it feels like nothing so much as fucking a hurricane. The sound in Leo's head is so terribly loud, a neuron-splitting current of noise: babbles, screams, shrieks, groans, sobs, hysterical laughter. He thinks one of his ribs might actually crack from the sheer force of it, and his cock sputters one last time, a pitiful little burst.
The thing just keeps pumping and pumping, filling him up with some kind of sharp-tasting fluid that pours into him like it's filled from a nose. The stuff spills out of him, trickling down Leo's scales and over the layers of his now cum now drying there.
He can feel himself being filled to the brim, clogging his throat so that his lungs burn. Can he drown like this? Would it be better for him, for everyone, if he did?
It doesn't give him the choice. The tentacles slide out of him abruptly, leaving Leo to gag and sputter as he tries to remember which way is up. He throws up Shub-Niggurath's come, feeling it splatter against the stones far below.
Hush, little one. Its voice sounds fainter, now, worn out. You did so well.
So well. Shredder and Kitsune were fond of praising him like that, too.. The words he hungered for--still does, really--have become linked to something dark and vicious in his mind. Leo suspects he'll be flinching at compliments worse than ever, now.
Distantly, Leo feels himself being lowered down, down, back down into the dark. He gasps as he's plunging into a pool of dark water, barely managing to take a breath before he's dunked beneath. He feels ropes of cum slipping out of him as he's shifted about in the water, cleansed in an unholy baptism.
It feels good, almost. At least, it helps the distant shrieking in his head die down a little.I will treasure these memories for millennia, my sweet, it murmurs as it lifts Leo back up out of the water. You will not live as long, but I will stay with you nonetheless, and I hope one day you will look back on these memories fondly.
Leo grabs for the few shreds of himself that he has left."Never," he rasps. 
Hmm. It tucks a tentacle back into his throat, gently petting his tongue. You know, the cultists will undoubtedly expect me to eat you tonight. Perhaps I will comply with their request, since they have given me such a lovely gift. You will not survive where I come from, but I might at least keep you with me.
There's something comforting about the fresh bolt of terror that shoots through Leo at the idea. The fact that he can still feel fear, that there is a part of him determined to endure all of this...it is not much, but it is all he has, now.
Do not fear. He's being carried through the air now, and in the distance he can hear chanting. They are expecting us. My worshippers, and perhaps your brothers, are waiting. We ought not to disappoint.
I have forgotten empires, planets, and entire galaxies. The voice is starting to slip away, as if it's too exhausted to maintain the connection anymore. A tentacle sweeps fondly over his cock, lapping up the last of the semen before tucking it into his shell. But I will not forget you, Hamato Leonardo. 
The door closes in his head, no doubt leaving another scar. Oh, well. What's one more?
Leo can feel the creature move, lifting him towards the dark. The chanting is getting loud, the stamp of feet and the babble of voices almost soothing compared to the aftereffects of the terrible noise ringing in his mind.
The grip on his body is weaker, now--it's clearly been exhausted by its pleasure. And he is too, so tired, but he has been tired before, has learned to stand on aching feet, to hold off the moment when he crumbles for as long as he can. That gives him an advantage.
His brothers will find him, as they always do and he will find them and keep them safe. He must. The monster was right, in its way. Better it happen to him than anyone else. And if the only way he can be assured of that is to stick around, then so be it.
They're moving into a new chamber, and Leo can glimpse a grim stone statue surrounded by hooded figures. Before that lies an altar, adorned with deranged-looking scratches and splatters of old blood. The old stereotypes are almost comforting after what he's just witnessed.
Leo tilts his head back, closing his eyes so doesn't have to see the tentacles wrap him in a cocoon as it sets him down. Wait, he reminds himself. The time will come. 
He forces himself to concentrate on that, to not think about how sore and slick he feels, how the inside of his head and heart resemble broken glass. He's sure he'll be able to handle it. After all, he's an old pro at this sort of thing by now.
(Even if it still hurts so much, every time).