Ye Olde Continuity Note: This story is set after Chapter/Issue 408 of the manga, and contains spoilers for it.
1You don't know when it was, precisely, that you began to wonder about him.
Maybe it was the night after your sword almost broke – again – and you cried in sheer relief (after the others were sleeping, of course) as you thought about what happened that last time you lost it – and what almost happened this time. Maybe it was during that most recent battle with Mouryoumaru, when you found yourself momentarily taken aback by the look in your brother's eyes as he vehemently insisted on fighting alone, or when he was hit with your stolen diamond blasts, and your heart seized in your chest, though you would deny that, if anyone should think to ask.
Maybe it was when you saw the scratches he'd received, despite the power of his sword, and you wondered, yet again, just what it was that drove him to fight an enemy that wasn't really his.
Yes, that's probably where it started.
You know that you had already begun wondering about him that time you fought Mouryoumaru for the final time, when over the shrieking of dozens of crystalline tentacles hurtling at you too fast to dodge, you heard Kagome scream, heard the others calling out a warning – and the tentacles shattered on a flickering red barrier, pinned to the space in front of you by a familiar-yet-unfamiliar blade, and you turned and saw his hand still outstretched, and he pinned you with another fierce, inscrutable look before recovering his blade and walking off.
He was certainly on your mind the day you and the others frantically searched out the source of a strange, sudden new surge of power that kept growing and growing – until it just vanished, as if drawn into a vacuum, and you burst out into a clearing, sword in hand, only to find your brother sheathing his, his back to you, and a smoking pile of bones and grave soil crumbled at his feet.
He was not the only thing on your mind the day you set off to face Naraku – but he certainly was when he appeared out of nowhere, swinging a blade at your chest. In that moment, you forgot that Toukijin was long shattered, you forgot that the only blade he owned would do you no harm – but he dodged your sword anyways, surprisingly quiet, and drove his sword through your heart – and you felt yourself filled with a strange, warm power, before he withdrew the blade and walked off.
You wondered, afterwards, after Naraku had fled again, how you'd managed to emerge unscathed, but for a relatively minor gash on your left arm. But your thoughts were too scattered to think of him.
You had not been thinking about him for a while when he walked out of the woods the last time – you were too preoccupied with the strange immortality you'd suddenly developed, too busy wondering what the catch was.
You looked at him, and you knew. He was the price.
He limped forward, and your first thought was that someone, somehow, however impossible it seemed, had finally gotten the upper hand in a fight. He just stared at you, though, that fierce, inscrutable expression on his face, and extended his sword to you, hilt first.
That's when it clicked. That's when you realized that every injury on him was one you should have received. Speechless, you look at him, and his gaze sharpens into a glare.
"They are reciprocal blades," he says, almost sharply. "You are the only one who can wield both."
As your hand wraps around the hilt of the sword he offers, he releases it and walks off without a backward glance, but you can sense the pall of the Underworld about him, and you know that this is the last time you will see him alive.
You wonder about him for a long time that night, while you stare at your newest blade.
Two days later, when the little imp and the little girl approach your group, one surprisingly subdued, the other jarringly cheerful, you don't have the heart to turn them away. You wonder if this is how he felt, if this is why he let them tag along, if this is why he bothered to protect them.
The imp begins to berate the girl, and you don't like the imp, but you, disconcertingly, find yourself agreeing with him – her happiness is bizarrely out of place.
Later that day, she tells you why. "He smiled," she says simply, and for once, there is nothing of the child in her tone, and you wonder if she is not grieving after all.
It is a long time, though, before you think about his gift again, though you've often thought of him. You are preparing for the next fight against Naraku – the battle that you know will end this war. You are holding your first sword, almost meditatively, when your gaze is drawn to the sword you still think of as his. Enlightenment strikes you, and you can almost hear his voice insulting your intelligence as he confirms your suspicions.
The next day, you face Naraku with two swords in your belt.
Naraku ignores your newest acquisition, the same way you ignored the same blade when your brother bore it. But when he could not harm you, when he could not flee through the barrier you generated, when your friends didn't stay dead – Naraku began to pay attention.
But his consideration had come too late. As the spider-scarred bastard moved, a brief sparkle caught your eye, and you lunged. Naraku dodged your outstretched hand – moving right into the path of your sword. The blade strikes the just-completed Shikon jewel – there is a flash – and your hunch pays off.
Crystalline light ripples across your sword as it absorbs the cursed bauble. The light is dull and tainted at first, but it purifies as you all watch, and finally – finally! – the light, the last trace of the Shikon no Tama, vanishes from this earth.
Naraku screams in rage, but he is nothing but a petty, weak hybrid now.
Later on, much much later, you find yourself back at the gate to the Underworld, and this time, the guardians let you pass.
You walk on, and then you see him.
He stares at you, face inscrutable, eyes fierce.
"I came to thank you," you begin, struggling for the unfamiliar words in this unearthly place. "You gave me so much ..."
"I gave you what you needed. An enemy to hone your skills, another sword to help fight Naraku. A barrier, immortality, an edge against your enemy. A third option for dealing with that damned jewel."
You look at him, and all the answers to the questions you've mulled over suddenly come to light. Straightening, you look straight into his eyes as you speak again. "You gave me more than that. You gave me a purpose, there near the end. You gave me my freedom, from choices I never wanted to face and circumstances I could not control. You gave me back the sanity I never knew was missing.
"But it's more than that, isn't it? What you said about the blades – they are opposites of each other. Which means that you sacrificed a part of yourself to keep me relatively sane all those years. Which means," and here you hesitate, unsure of the conclusion you have reached, but still feeling, deep down, that you are right, "that you lost your ability to live without your sword ... when you gave me the ability to live without mine."
He smirks, such a familiar – such a missed – expression that you have to restrain yourself from grinning. "You are not the only one able to acquire new powers for your sword." His gaze sharpens on your face. "What are you really doing here, Inuyasha?"
You have not lost eye contact since you began your impromptu speech, but at the demand in his voice you find yourself assuming a far more solemn demeanor than any of your many acquaintances would have ever thought possible. He looks mildly surprised himself. "I came to ask you what you want done with this," you say, holding out his blade. "Now that I've beaten Naraku..."
He interrupts you. "And is Naraku the only enemy you will ever face? The sword is meant to be used, as is its brother. Neither blade ever deserves to be locked in a tomb, with nothing but ghosts for company." He turns to go.
"Wait – " you begin, and he turns, exasperated at you for dragging out this conversation, and the expression on his face is so him that your eyesight goes blurry (not that you'll ever admit to it). "There's one more thing you gave me," you continue, suddenly unsure if you should even say this. But he is looking at you expectantly, and so you force yourself to finish the thought. "You gave me your love," you say, mortified at the crack in your voice.
You never see him move, but suddenly you find yourself wrapped in his barely-substantial arms (and it only just dawns on you that he has two again), cradled to his chest as if you were still a small child. "No," he says, and there is a crack in his own voice. "You're wrong. I never gave you my love." He draws back, looking at you with mist in his own eyes.
"You always had it."
He vanishes at that, but you can feel his presence as you sheath his sword, and you know that he is watching you as you return to the world of the living. But the fierce gaze, no longer unreadable, is a comfort now, not a mystery, and you feel a twinge of guilt at how badly you had misread him – but the memory of the warmth in his eyes just now calls up a sense of gratitude that staggers you, and you are glad you got this brief chance to see him as a whole being, instead of the shell that had fought to aid you in life.
You cross the threshold, and Rin practically bowls you over with an enthusiastic hug. Shippou teases her, but his eyes follow you, as do the others'. You ignore them, hand on the hilt of a sword that, even after all these years, still feels strange to you, still bears the ghostly imprint of his fingers, and you move over to the trees, to the one figure that hasn't moved since you've left.
Jaken looks up at you, death-thick weariness clinging to him. "Did you see him?" the imp asks, in a broken parody of his former croak.
You nod.
"Is he well?"
"Yes," you say, because it's true – and Jaken knows it; he can read it in your face. He nods, then looks up at you. "I think it is time I join him."
You nod again, having expected nothing less, and Jaken gives you one of his odd smiles. Stiffly, he rises, looking more like an ancient human than a youkai, and moves to the gate you have just passed through. Its guardians watch the small imp warily, but he only smiles at them. Jaken touches the gate, and is no more.
You watch the gate for a moment longer, then turn back to the others, your eyes uncharacteristically somber. "Let's go." You do.
It is a long time before you can bring yourself to release Tenseiga's hilt, but you find that you don't need to wonder anymore.
Author's Note: I've long ascribed to the notion that Tetsusaiga and Tenseiga are meant to be opposite blades, wholly and completely. We actually get surprisingly little information about Sesshoumaru's sword in the manga, but what little we do get supports this notion: it revives 100 youkai while Tetsusaiga kills 100; it can be held by a youkai, while Tetsusaiga can't be -- heck, it's even Tetsusaiga's opposite when it comes to transformation -- Tetsusaiga needs to transform to be used, Tenseiga has (so far as we know) only one form. I've extrapolated from there.
