Grimmjow x Ichigo (eventually)

AU; in the sense that Grimmjow comes back. A little speculation, but nothing major. I've taken certain liberties with how he could return. Eventual M-rating.

Prologue

The white sands of Hueco Mundo shifted underneath the heavy tread of his feet, and the walker let out a guttural groan as he had to push harder and harder to force his way up the bank of a steep dune. The sand had edged its way into him, as it always does, and he felt like the first layer of his skin had been scraped right off him by a brutal and uncaring barrage of sandpaper. There was something raw about his wounds, and he felt terrifyingly weak, and he could taste the desert in his mouth, parched. His tongue flickered out to wet his lips, but it was a futile effort, and was met with the taste of more sand.

He reached the top the dune he was currently battling- battle? Through the haze of pain, he was sure that there had been a battle. Wasn't that all the power he could feel around him, power that was not his own? He shook his head, staring around him, and all he could see was more of the same, stretching out towards the horizon.

No battle, no buildings, no people.

Exactly what he wanted.

The moon was glowing above him, looking bloated and obscene in the dark sky. Nothing to comment upon, though- if you lived in Hueco Mundo, you did not comment on the presence of night time. It cast a silvery light across the barren land, illuminating his hands as he checked them. They had been pressed against his chest for the last few hours, ignoring the ache in his arms, which were screaming to be moved. They had felt the ridges of his skin, torn apart, and he had been struggling to keep the frayed edges of his flesh together; a desperate attempt at healing.

His hands were wet, but under the near-unnatural bright light, the blood did not look red.

He pressed his hands briefly to his mouth: liquid, sustenance, beautiful (if the Arrancar had any understanding what beauty was).

He propped himself against the trunk of a shrivelled looking tree, not caring that his blood was staining the quartz, and refused to slump to the ground. His mind became a little clearer as he stilled, and the pain lifted just a bit. He knew that the only reason that he had not been set upon by hollows up to now was that most of them were cowering in fear at the immense amount of spiritual pressure coming from Las Noches. The battles were still raging on, but the further away he pushed himself, he better he could hide.

Unfortunately, the further away he was the less cautious the hollows became. A small, rat-like creature crept towards him from where it had been hidden in the shadow cast by a boulder. He unsheathed his blade, and stabbed it through the hollow's mask, disintegrating it in seconds. Propelling himself with an inelegant movement of limbs he took the hollow's place, leaning against the rock which would provide him with a little more protection than the tree. He let his head fall forwards, to his chest.

He coughed, hacking, and spat blood. It seeped into the white sand, leaving dark stains against the ground.

He could feel the power seeping out of him with each drop of blood, and as he closed his eyes he gripped the hilt at his hip in a tightly closed fist. He had a feeling that he would not be able to do even that, soon enough. He fell to his knees, and then to the ground, pulling his legs up against him, pressing them against his wounds.

He was sinking, sinking back into darkness, and it felt a little like he was falling.

Things did not make sense.

He spent a while- how long? how much time was passing?- underneath the unchanging moon it was hard to tell- curled up in the shadow of the rock, listening to the sounds of power echoing over the sand from Las Noches. He listened to Ulquiorra fight, and then the bastard cero Espada- and who knew the bastard would be so strong? Kurosaki was there too, although it took him a moment to remember why such emotion rose up in the back of his throat like bile when the name floated across the boundless stretches of his mind. When they both fell, he was left to feel the shaking reverberations from the battles going on elsewhere in the human world, ones that rocked the very foundations of Hueco Mundo, because this battle would decide the fate of it, and the world itself could tell.

When even that dissipated, in a great blast of spiritual pressure that made the sand dance in front of his wavering vision, he closed his eyes.

It was over.

The shinigami had won.

At that, the creature curled up in the sand let out a howl, his muscles contorting and contracting as the last of his power seeped out of him, and he reverted. He could feel his spine lengthening, his skull expanding and his limbs changing, and soon his howls were no longer of rage, but of pain, instead.

A few days later, an Adjuchas-class Menos pulled itself to his feet in the shadows of the boulder. The Menos hungered. Curious hollows that had gathered around him scurried away as he growled, lips curling to reveal clenched teeth, sharp and white. His hooded eyes stared out across the sand, trying to readjust itself to his old body, to having to walk on four legs again. His tail brushed against the back of his legs, and his fur bristled, muscles clenching.

Soon, there were no hollows left nearby, and the Menos was stated. He fell back to his haunches, and licked the lingering wounds that lacerated his body, although most were healed. Only remnants of the deepest ones were left, and underneath the fur, the scars would not show.

He remembered when he had first generated into a Vasto Lorde- no scar at all had been left that time.

Was this the fate of the Arrancar who lost too much power? Would they revert back into something less substantial than what they had been? And if that was the case, then what would happen to Ichigo, with his scent that was Arrancar but with more Shinigami, and that lacerating hint of human mixed in.

And how long would it take him to be Vasto Lorde again? The same agonising stretch of years, decades, centuries… or would his body remember how to do it?

The creature stalked the sands of Hueco Mundo for days after that, until time became irrelevant and each dead hollow he consumed blurred into the next. He felt somewhat lost in this world now: his was disenchanted with these sands. Was there anything for him, here? He could eat, he could live, but he was not sure if that was enough. He cursed Aizen- in creating him as an Arrancar, in developing his mind, he had made his own, old life seem entirely futile.

He needed to be a Vasto Lorde again, but he did not want to change here. He no longer wanted to stay in this place, a beast under the moonlight.

So, when he saw the tail of another Menos disappear between rips in the air, he ran towards it, legs blurring as he kicked up sand behind him. He jumped through just as it was closing, and ignored the shinigami battling with the two that had come through before him. He remembered, somewhere in the back of his mind, how to suppress his power, and he was glad, knowing that that meant he was getting stronger again, and that the powers of his previous life still lingered with him.

He slipped away, unnoticed, as reinforcements came.

In this human world he padded through the trees of an unknown forest. He could smell humans in the distance, the undeniable cloud of engines and carbon and filth.

There were other things too, familiar things, and in a moment he knew exactly where he had arrived.

Karakura, huh?

Padding towards the humans he tasted the air, and the beast let a snarl that was almost a smile curl over his jaw.

Grimmjow was back.

TBC

I'd love some feedback on this. There will be more chapters, if there is enough interest.

Thanks for reading. NT-x