Tails sat there for a long time, letting the feeling of relief sink in as his mind caught up to everything that had happened. Sonic was still unconscious, but his breathing was steady and he had no visible wounds. Whatever the Chaos Emeralds had done to return him to normal had also repaired the damage from his fight with Blaze and Silver. That was a relief.
The Chaos Emeralds had also replenished the Wisps' energy and vivid colors, and now they were flitting about with their usual noisy enthusiasm. Or, most of them were. Some of the Wisps—Yakker included—hung back, watching their compatriots with weary irritation; Tails guessed those were the ones who were connected to the Sol Emeralds and Time Stones, and thus hadn't benefitted from the Chaos Emerald boost. He still had a lot of questions about the connection between the Wisps and the Emeralds, and maybe now he'd finally have time to investigate.
"Can you guys check on Blaze and Silver?" Tails asked Ember. He was reluctant to leave Sonic unattended even for a moment.
Ember chirped affirmatively and flew over to prod at Blaze. The other Wisps—or the ones who'd been reenergized, anyway—joined in, poking at both Blaze and Silver with their stubby tentacles. Tails assumed they were sharing their energy, but it was just as likely they were waking them up the old fashioned way: through persistent annoyance. Gradually Blaze's eyelids started to flutter, and after a few moments she sat up with a grimace, clutching her side. Silver woke up a few moments later, looking none too pleased to be back in the world of the living.
"Where—" Blaze started, then her eyes widened and she scrambled to her feet, stumbling slightly.
"It's okay!" Tails called. "We're safe!"
He could hardly believe the words. They were safe. He'd done it; he'd defeated Eggman and Nega-Sonic both, without losing anyone. Almost anyone, he remembered with a twinge of guilt. He hadn't known Black and White, but Blaze and Silver had clearly cared for them.
Blaze approached slowly, eyeing Sonic's unconscious form. "Is he…?"
"He's fine, as far as I can tell," Tails said, leaning forward to check Sonic's pulse again just to reassure himself. "The Chaos Emeralds did something. I don't know what, but…'" He gestured at Sonic. The results spoke for themselves.
Blaze hummed, kneeling down to check Sonic over for herself. "The Emeralds were under Nega-Sonic's control and Eggman's influence. For them to break from that, they must have felt a very strong will." She looked up at Tails, and he glanced away shyly. "Strong-willed" wasn't how he'd ever describe himself, but… well, if it worked, it worked.
"Should we check?" Silver asked. He'd gotten to his feet, though from the way he squinted his eyes and clutched his head Tails guessed he was suffering from a bad migraine. He gestured with his free hand at Sonic. "He might still be… you know."
Tails hadn't considered that. He'd been fooled by a form change before; it wasn't out of the question that Sonic might still be under Eggman's control.
"{Wake up,}" Tails said in Mandarin, nudging Sonic's shoulder. "{Can you hear me?}"
It took a moment, but Sonic's eyes blinked open. Emerald green, bleary and yet with a spark in them that hadn't been there when he was under Eggman's control.
"{Tails?}" he asked—asked in Mandarin. It wasn't a confirmation, exactly, but it still filled Tails with a rush of relief. Sonic sat up, blinking owlishly over Tails's shoulder, and switched to English like he usually did when they had company. "Wait, is that Silver? What're you doing here?"
"You're welcome," Silver said irritably, then yelped as Blaze stepped on his foot.
"How are you feeling?" Blaze asked, ignoring Silver's glare.
"Like I was hit by four separate trucks in succession," Sonic grumbled, rubbing his head.
"How much do you remember?" Tails asked.
Sonic's ears flattened, and he looked away. "Everything."
Ah.
"Do you know how Eggman…" Blaze seemed to struggle to find the right word. "Controlled you?"
Sonic frowned, brow wrinkling in concentration. "There was a machine… It was like what he used to wake up Light Gaia, a few months ago. But it wasn't Light Gaia that took over. And then there was this… tearing feeling." He shuddered, wings fluttering unhappily.
"A conduit," Silver said thoughtfully. When they looked at him, he explained, "That's what Argus—uh, someone in my world—said. 'A perfect conduit for chaos.'"
"That sounds like Sonic," Blaze muttered.
"She also said something else," Silver continued. "That being a conduit makes you vulnerable."
Blaze nodded slowly. "It would make sense. Sonic opened himself to both Dark Gaia and Light Gaia; he may have accidentally made himself vulnerable to… other things, as well."
"Like a mind control machine," Sonic suggested dryly. "But it didn't work perfectly. Something went wrong."
"Eggman wanted to use your abilities for himself," Tails said, recalling what the doctor had said during their fight. "The Emeralds realized that and hid on the Little Planet, out of your reach. And the Gaia energy…" he trailed off.
"Went to another dimension," Blaze said softly.
"And another timeline," Silver finished grimly.
The pieces fit together. Hedgehog, lion, wolf. When Sonic had been under Light Gaia's influence, he'd become some sort of hybrid of hedgehog and cat… or hedgehog and lion. Then when Dark Gaia's energy joined the mix, he'd gained several wolf-like traits. Those energies—extensions of Pretzel and Whip, back on Earth—had been mixed in Sonic, intertwined in his body and mind. When Eggman had used his machine, those energies had fled or been expelled into different places and times—and they'd taken parts of Sonic with them.
Had Black and White really been people at all, or had they just been the Gaia energy trying to recreate the person that once held it? They'd likely never know.
Tails decided to dwell on that existential crisis later. "So if your new form makes you vulnerable to something like this, then… How do we stop it from happening again?"
"You could use a limiter band of some kind," Silver suggested. He extended his wrist, showing them a thick gold bracelet with glowing cyan banding. It wasn't unlike the limiter rings Shadow wore. "Gold—a friend of mine—made these for me. They help focus my powers and protect me from other psychics."
"I had something like that as well," Blaze said, taking something from her satchel. It looked like a white and pink shawl, tattered with age. She held it gently. "When I was a child, I used this to help control my powers."
"Can I look at those?" Tails asked. Silver nodded and unclipped one of his limiter bands, handing it to Tails. Blaze hesitated, looking down at the shawl with something like grief, before she nodded and pressed it gently into his hands. Tails pulled out his Miles Electric, the gears in his mind already whirring. "We need something to help regulate the energy Sonic conducts, to make sure nothing unwanted can get in." He looked at Sonic. "Do you care what it looks like?"
Sonic shrugged. "As long as it doesn't get in the way of my running."
"And it needs to stay on even if your form changes," Tails said thoughtfully. "I think I have an idea."
Fortunately, there was a surplus of materials in the space station. While Blaze and Silver recovered from their injuries—the Wisp energy helped, and it helped even more when the Wisps fetched the Sol Emeralds and Time Stones from Little Planet—, Sonic jumped at the chance to fetch whatever Tails needed. That was one thing that hadn't changed; Sonic dealt with things best when he was running. And when Tails ran out of errands, Blaze—who had decided, against everyone else's better judgement, that she was done resting—challenged Sonic to a spar. Silver wisely opted out, instead choosing to investigate the space station (and, Tails suspected, to see if Eggman had any ibuprofen).
After the first two broken monitors, Tails banished Sonic and Blaze from the lab so he could actually focus on his project. Silver came back from his exploration to loiter around Tails's workspace, getting in the way and clearly trying to avoid Sonic, so Tails enlisted him in his project and, with Silver's input (and use as a guinea pig), at last put the finishing touches on his creation. All that remained was the final test.
Tails found Sonic and Blaze arguing in the corridor outside the lab. The metal around them had been scorched and scratched, and a smoke alarm blared overhead (the other alarms had been destroyed). At least they'd had the sense to fight away from the windows.
"I totally won that round," Sonic was insisting.
"You're delusional," Blaze shot back. "I had you surrounded. That is not a victory."
"I could have run through the flames, easy."
"Sonic," Tails called, and was ignored.
"You didn't have the space to build up enough speed. It's simple math, Sonic. You couldn't have escaped."
"Sonic," Tails said again, more insistently, and was again ignored.
"So I might have gotten a bit burned, but I still could have escaped."
"Getting set on fire isn't a victory, Sonic."
"This coming from you? Your entire moveset—"
"Sonic!" Tails snapped, and they both sheepishly looked over at him. Tails lifted his creation in the air, waving it. "I finished."
"Oh!" Sonic's ears pricked forward. He walked over, picking it up cautiously. "It's a… scarf? With… pieces of metal sewn into it?"
Tails nodded proudly. "It's fashionable and functional. Put it on."
Sonic hesitantly wrapped the scarf around his neck. "Now what?"
"Close the rings," Tails said, bouncing up and down giddily.
Sonic fiddled with the scarf until he found the gold rings sewn into the ends, open like Silver's bracelets were when they were unlocked. Sonic clicked them both closed and gasped. They all yelped and scrambled back as Sonic's wings turned into what looked like white smoke before disappearing entirely.
"You dissolved him!?" Silver gasped, whether in alarm or awe, Tails couldn't tell.
"I'm dissolving!?" Sonic shrieked, whirling to try and see what they were looking at—a futile effort, given it was happening on his own back.
"I did not, and you aren't," Tails insisted, then hesitated. "Or, um, you shouldn't be."
Sonic stared at him incredulously, which was patently unfair. The scarf hadn't dissolved Silver, had it? Besides, it was already stopping. Much to Tails's relief, only Sonic's wings and long tail disappeared, leaving a shorter tail and Sonic's usual back quills in their place. It wasn't quite Sonic's usual form; the shade of blue was slightly off, his fur was still fluffier, and his tail was still longer. But that hadn't been the goal, anyway.
"So… how do we test it?" Silver asked after a moment of silence. "Do you have a mind control ray or…?"
"No," Sonic said immediately. "No mind control rays." He looked at Tails with near panic. "You don't have a mind control ray, do you?"
"Not yet," Tails said, and grinned at Sonic's alarmed expression. "But we could still test it. Sonic, you can usually feel the Sol Emeralds' energy, right?"
Sonic nodded.
Tails looked at Blaze, and she called one of the Sol Emeralds into her hand and lobbed it at Sonic without further warning. He nearly dropped it—earning him a reproachful glare—before gripping it securely in one hand. He held it up carefully, studying it.
"Do you feel anything?" Blaze prompted.
Sonic shook his head. "Might as well be a paperweight." He tossed it back to her.
"Okay, and now let's try a Chaos Emerald," Tails said. He took the cyan Emerald from his subspace and tossed it to Sonic, who at least caught it with more grace this time. "How's it feel?"
"The same as always," Sonic said. "Bright."
"This still doesn't prove he can't be mind controlled," Silver pointed out.
"That's true," Tails admitted. "Which is why I put several sensors in Sonic's scarf. They'll record data about any sort of energy he encounters, so if he starts acting weird again I can check the records to see if something changed and where it happened."
"You microchipped me?" Sonic demanded.
"You absolutely deserve it," Blaze said. "This is the second time you've been tricked by Eggman and gotten brainwashed because of it, Sonic."
Sonic huffed but didn't argue.
"If that's settled," Silver said, shifting impatiently. Or uncomfortably? "I need to get back to my own time." He turned as if looking for someone, but then stopped himself.
"Good luck, Silver," Sonic said quietly.
Silver glanced at him, then sharply looked away, summoning the Time Stones and disappearing without so much as a goodbye.
"I should be going as well," Blaze said. "Marine will be worried." She hesitated a moment, then stepped forward and gently bumped heads with Sonic. It was a common gesture of affection between cats, Tails had heard, but he'd never seen the ever-formal Blaze do it. "Stay safe, Sonic. Keep in touch." She called the Sol Emeralds to her and vanished in a blinding flash.
"What now?" Sonic asked, turning to Tails. "Back to Earth?"
"Actually," Tails said, looking at the Wisps hovering nearby. Ember hummed, and Tails smiled. "Why don't we stick around a little while longer?"
Sonic smiled back. A real smile, not a plastic grin. Tails had missed it. "Sounds good to me."
This time, they went through the portal together.