This was it.
Sonic collapsed against a cluster of bone stalagmites, body trembling with shock from too many wounds to endure, even with the red motes of energy he'd managed to scoop up from the various monsters of the cave while he'd been fighting.
There were just too many of them. On their own each Zeti was brutally strong, fast enough to be a problem, and resilient enough to shrug off all but the heaviest of blows. With five at once Shadow and himself simply couldn't apply enough damage to take one down for good before the others cut them off, giving their tainted flesh time to regenerate.
And meanwhile every graze, every bump, left Sonic that much slower, that much easier to hit until finally his body refused to cooperate altogether.
And all the while the corruption grew stronger within him.
"On your feet!" Shadow roughly yanked Sonic's arm as he skated past, dragging him out of the way just as a bolt of glowing red energy blasted into where he'd been in a shower of bone shards.
"Thanks." Sonic stumbled unsteadily away from the remaining salvo as they streaked from an almost unrecognisable Zeti's distorted claw.
"Shut up and fight. I can't do everything myself." Shadow pushed away, leaping up to unload a pistol into the face of… Was that Zavok? Didn't matter, apart from size they were barely distinguishable. Bloated red and black flesh with gaping oversized mouths oozing a constant trickle of phlegm down their bodies.
The Zeti retaliated, backhanding Shadow away with a contemptuous flick of the wrist. He bounced back to his feet panting heavily. While he wasn't visibly hurt - Sonic had seen the black hedgehog shrug off gunfire without a scratch before - he was slowing down too. His attacks were becoming less frequent, less accurate as the constant barrage of abuse whittled away at his stamina as the fight went on.
But… they still weren't dead. It was almost as if the Zeti were toying with them, taking turns to attack leisurely rather than working together to simply overwhelm the two of them, and they certainly had enough power to do so if they'd wanted. Knuckles himself hadn't even bothered to rise from his eyeball encrusted perch since they'd arrived.
He didn't understand. Was it just some sadistic game for them? It wasn't like they could escape. Well, maybe Shadow could with his rocket skates, assuming he had an opportunity. Or did they want him to use Chaos Control and open up another rift?
A massive palm caught Sonic in the shoulder, slamming him across the cavern in a tremendous spray of water as he smashed through the waterfall and into the wall beyond, dropping to the floor on the far side of the shallow stream.
Sonic groaned, rubbing his head with trembling fingers as he lay on the ground. The dim blue light of a fading flare sputtered nearby, a testament to how long they'd been struggling down here in the dark.
If only he-
"Do you seek power now?"
The soft voice spoke into his ear, cool fingers lifting his head from the stone, chilling his skin even through his fur.
"T… Tikal?"
The echidna's glowing eyes glittered brightly in the gloom.
"You need only say yes, Sonic the Hedgehog. The power you need-"
"Get away from here, Tikal." Sonic forced himself to his feet once more.
A flash of energy exploded from the other end of the cave. Shadow skidded across the floor once more, smoke rising from where he'd been too slow to dodge a blazing projectile.
Tikal frowned at him.
"I cannot show the way for those who do not seek power."
"It's too dangerous here."
"Then that is your choice, Sonic the Hedgehog. There will be others."
A finger brushed his cheek, burning heat sizzling painfully where she touched for a moment and then she was gone, as though she'd never been. Sonic yelped, rubbing at his cheek.
Six pairs of eyes turned to stare in his direction in unison.
"... What?" Sonic glanced around. "Something on my face?"
"It seems you have exhausted her patience, Sonic." Knuckles broke the silence with a mighty clap of his hands, shrouded in shadow at the far end of the cave. "But have no fear! There is mercy too in Mother's arms. We will be brothers henceforth!"
"And look like these guys? No thanks! I'd come up with a yo mama joke but she already is one."
The echidna spanned his fingers. All five Zeti charged as one. Sonic grimaced. Looked like playtime was up. At least while they were focused on him Shadow could get out of here. And hey, maybe it wouldn't be so bad being a grossy face monster while Tails figured something out back at his lab to change him ba-
The closest Zeti shrieked, tripping forwards into the water as its legs gave out underneath it. Sonic blinked in surprise as the remaining Zeti fell over themselves trying to stop from joining their writhing kin as it thrashed over on itself, wailing incoherently.
And then Sonic felt it.
The Zeti in the water was disappearing from his corrupted senses, leaving a void in his awareness that was faintly disorientating.
"Hello, boys!" A familiar sultry voice called out from above.
"Rouge!" Shadow cried out from somewhere behind the crowd of Zeti.
"Need a little help, handsome?"
A white beam of light shone down from the passage above, revealing a cascade of green liquid pouring down in a thin stream. Zeti screamed as the light and liquid caught them, even the tiniest of droplets causing crimson flesh to peel away, leaving the more familiar, if just as alien, hues of the normal Zeti beneath.
"Tails did it!" Sonic let out a triumphant whoop as he dropped to one knee in relief, watching flesh and bone wash away into ordinary rock as the green spray spread its way across the floor of the cavern.
More lights illuminated the cave, human G.U.N. troopers slid down into the cavern on ropes, their flashlights and shouts filling the cavern both. Sonic finally caught sight of Rouge, flying above, white furred and pure once more, the golden portal ring in her hands the source of the green stream of salvation.
A boulder of flesh hurtled through the cave, smashing into Rouge from below. It turned to ordinary rock even as it knocked the unfortunate bat out of the sky. Shadow leapt through the air to catch her just before she landed, the portal ring spinning to the earth in a spiral of green.
Knuckles.
He stood before the flesh altar, surrounded by energy as he held out his arms, red tendrils snaking from his hands to join with its fleshy surface. Bullets punched uselessly into his flesh as G.U.N. soldiers opened fire. The air above the altar began to shimmer.
"You are too late, thrall of Iog-Sotôt! Our duel is done! The great feast is at hand!"
"No!" Sonic threw himself into a run, stumbling forward on shaking legs. Green-tinged water sent burning agony up through his entire body but he kept moving, scrambling over fallen Zeti. Too slow. The shimmer became a sickly red glow, bloody liquid gushed forward from Knuckles body from a dozen bullet wounds, a rapid spray that dropped a G.U.N. trooper to the ground, multiple fresh limbs erupting from her body to form a flesh spider.
Sonic kept running, willing his limbs to move faster. He scooped the portal ring off the ground, its endless fountain of purifier no longer painful as it washed over his fingers and he swung, green clashing with red, a swirling boundary as the two fluids neutralised one another, sticky yellow liquid splashing under his feet.
Knuckles gazed at him, silhouetted against the now almost blinding light behind him. He held his hand out to Sonic, fingers almost lost between the fleshy veins that connected him to the altar. Sonic braced himself, too late to dodge.
"Froggy!"
"What?!" Knuckles turned with a roar of surprise as a small green frog hopped up onto the altar from behind him.
Almost instantly the light winked out, the frog doubled in size, then doubled again, and again. It let out a thunderous croak, slapping its tongue into Knuckles' chest with incredible force, tearing him free of the altar to crash to the floor in a spray of blood.
And Sonic was there a moment later, holding the portal over his friend's face to douse him in purifier. Knuckles roared in pain, swatting him aside as he surged upright, flesh dripping off him as he sent a flaming fist at the frog on the altar, oversized veins stretching out towards it like tentacles.
A blue flail hurtled from the darkness, cracking directly into his skull. Knuckles wobbled, turned, and finally fell to the floor, letting out a wheezing groan as his overmuscled frame sloughed off to reveal his original mobian body beneath.
Big lumbered out of the shadows, stepping vacantly over Knuckles' prone form, his yellow eyes focused solely on the giant amphibian.
"There you are, Froggy! Let's go home."
Sonic shook his head in disbelief, panting heavily as the odd duo vanished into a side tunnel, leaving the altar, and its champion, silent and still. Without Knuckles spraying fresh crimson everywhere, and with the portal ring now on the floor, spraying up purifier like a geyser, the cave and its occupants were returning to normal at a rapid rate, the danger had finally passed.
Sonic slumped down on the floor in exhaustion, letting the green rain wash over him as more G.U.N. troopers leapt down from above, rushing to secure the Zeti before they recovered their senses.
"Sonic?" Violet eyes peered at him. "What was I..." Knuckles trailed off with a frown, straining to try and lift himself from the floor and failing. "Wait, where are we?"
Sonic grinned weakly at his old friend as a medic pulled him onto a stretcher, shouting for a ring monitor.
"Good to have you back, Knucklehead."