In the anime, Ash and the others were supposed to have discovered Crystal Onix here. From what the episode showed, Crystal Onix was transparent—basically invisible in water, the perfect camouflage.
If it was really in this deep pool, you wouldn't spot it with the naked eye. Reiji did have a way to confirm it, but that only mattered if there actually was a Crystal Onix down there. If there wasn't, then no trick in the world would help.
Splash—
Reiji's method wasn't "send Poliwhirl and the others in to search." That was asking for trouble. Barging into Crystal Onix's territory—if it got angry, they'd all pay for it.
So he threw a pebble into the pool. In the silence of the cave, the splash echoed sharply. His flashlight tracked the ripples spreading across the surface, the beam sliding outward with the waves.
Then the ripples hit something—like an invisible wall—and rebounded. Reiji froze the flashlight beam on that exact spot.
No way… it's actually here? His luck wasn't bad. The light showed nothing near the surface, no outline at all, but that rebound was too clean. The water had to have struck something transparent.
Still not satisfied, Reiji picked up another stone and threw it straight where the beam pointed. It clacked against something hard and invisible.
That sound wasn't a splash. That sealed it—something was definitely hiding there, and it wasn't an "air wall."
So you're playing dead, huh? Reiji almost laughed. It was right there, not moving, pretending to be part of the scenery—while being completely transparent.
"Poliwhirl, Kingler—use Mud Shot where the flashlight is shining."
"Poli, poli—pfft pfft pfft!" Poliwhirl fired mud into the air. It didn't fall into the pool. It splattered against something unseen.
Kingler followed, spitting mud as well. With both of them firing again and again, the mud started to cling—and a faint transparent outline began to appear.
"Rooo… roo…" Crystal Onix had been watching, curious about what this human was trying to do. Plenty of humans had ignored it before. This one was different.
But the moment Poliwhirl and Kingler started spraying mud onto its body, it snapped. Even if it wanted to stay hidden, it couldn't anymore.
"Not good. Move!" Reiji saw the transparent monster finally stir and roar loud enough to shake the cave. He spun on his heel and bolted, shouting for his Pokémon to run with him.
They'd barely reached the tunnel when everything went quiet behind them. Crystal Onix didn't chase.
What the hell… so much noise, and it was just trying to scare us? Reiji brought the three Pokémon back cautiously to check. The pool was murky now, but Crystal Onix was gone without a trace.
"Poliwhirl, Kingler—you two stay here and keep provoking it. Lure it out of the cave. Scyther and I will wait outside. Remember: if you can't handle it, run. Just pull it out, then we jump it together."
There was no way Poliwhirl and Kingler could deal with an enraged Onix head-on. And if it did chase, Reiji wouldn't be able to outrun it in the cave anyway. Better to set the trap outside.
He'd only come in to confirm whether Crystal Onix was here. Now that he knew it was real, everything got simpler.
Make it mad. Catch it. Once you've seen it with your own eyes, there's no way you leave it for someone else.
Reiji and Scyther left the cave first and waited quietly in the forest outside, listening for Poliwhirl and Kingler to draw it out.
"Poli, poli…" Poliwhirl watched Reiji go, then turned back and copied what Reiji had done—tossing pebbles into the water to see where ripples might rebound.
Poliwhirl did have a kind of moisture sense, but that only helped with things that moved. If Crystal Onix stayed perfectly still, the "sense" couldn't tell what it was. It was like Zubat's echolocation—useless if you didn't know what you were looking for in the first place.
This time, the ripples didn't rebound at all. That meant Crystal Onix wasn't near the surface anymore. It had probably sunk to the bottom.
"Poli, poli?" Poliwhirl looked at Kingler, asking what to do. With Reiji outside, how were they supposed to lure Crystal Onix out?
"King… king…" That question was a little too cruel. Kingler was a straightforward kid—no clever schemes.
"King…" Seeing Kingler had nothing, Poliwhirl had to think for itself. It glanced around, then noticed the pool had turned muddy. An idea hit.
"Poli! Mud! Stones! Make the water filthy—mess up its home!"
"King. Okay." Kingler started digging sand with its claws and dumping it into the pool, polluting the clear water.
Poliwhirl kept spitting mud to make it even murkier, while also throwing every stone it could find into the pool.
Then—
"ROOOO! ROOOO!" Crystal Onix burst up again, head and upper body rising from the pool, roaring at the two of them like it was asking if they were done yet.
What it got in return was, "Poli—pfft pfft pfft!"
Three Mud Shots, straight into Crystal Onix's face.
"ROOOO!" That was it. Crystal Onix completely lost it. Not only were these two pests ruining its sleep, they were spraying mud all over it. It surged out of the water, jaws wide, lunging to bite them.
"Poli poli! Run, run!" Poliwhirl grabbed Kingler and fled.
They dashed out of the cave entrance… and realized Crystal Onix hadn't followed.
Reiji felt the ground trembling for a moment, then it stopped instantly. This Onix was ridiculously homebound—it only wanted to stay inside its crystal cave, no matter what.
So Reiji had them go back in again. More provoking. More baiting. Drag it out.
If Crystal Onix wanted to be that stubborn, he'd be stubborn too. If they could lure it out, he'd catch it. If not, he'd walk away.
There was no way he was fighting it inside that cave. That was Crystal Onix's home turf. Even if Poliwhirl, Kingler, and Scyther tied themselves together, they still might not win.
"Poli…" Poliwhirl went back into the cave again, but this time it told Kingler to rest outside. They were going to grind it out and take turns.
Back and forth they went—Kingler, then Poliwhirl, then Kingler again. Over and over. Crystal Onix refused to be drawn out.
Once, Reiji even saw its head glittering in the sunlight at the cave mouth… and then it immediately retreated again.
To Crystal Onix, these two pests were worse than flies. After being harassed more than a dozen times, it finally exploded. It charged straight out of the cave, determined to bite the two troublemakers to death.
What it ran into instead was a three-Pokémon ambush—and Poliwhirl even blocked the cave entrance, cutting off its retreat.
"Kingler, Mud Shot—slow it down! Poliwhirl, Ice Punch—hold the cave entrance! Scyther, Agility into Fury Cutter!"
"ROOO!" Crystal Onix sensed something was wrong. It had been tricked. The cave was blocked, and the way back was sealed. It immediately tried to Dig and escape.
As if Reiji would allow that. You came out—so you're staying out.
"Kingler, clamp its tail! Don't let it get away!"
"King!" Kingler stopped firing Mud Shot and lunged in, gripping Crystal Onix's tail with both claws. Its legs dug deep into the soil, carving long grooves as it braced and hauled with everything it had, forcing Crystal Onix to stay put.
"Poliwhirl, Ice Punch—go! Hit its head!" Reiji snapped the order the moment he saw it trying to flee.
If it was immune to Water-type moves, fine. He had Ice, Fighting, Ground, Steel, Grass—plenty of options.
Onix had weaknesses everywhere. He didn't need Fire to take this thing down.
"ROOO!" Crystal Onix tried to shake Kingler off so it could Dig, but the instant it lifted its head, Poliwhirl's Ice Punch smashed down. It howled in pain.
Scyther didn't let up either. Its scythe arms flashed again and again, Fury Cutter stacking fast—power climbing all the way up to 160.
Under the nonstop pressure from Poliwhirl and Scyther, Crystal Onix's eyes rolled back. It crashed into the trees hard enough to snap several trunks.
From start to finish, it never properly fought back. It only wanted to escape. If it had stood its ground and counterattacked, the three of them wouldn't have had such an easy time.
Once Crystal Onix was down, Reiji pulled out a Poké Ball and threw it.
The red light on the button flashed three times… then went still.
Caught.
He hurried over, picked up the Poké Ball, and immediately opened Crystal Onix's proficiency panel.
Crystal Onix (Shiny)Type: Ice + GroundGender: FemalePotential: 48%Level: 41.44%Ability: Sturdy / 34.35%Moves: …
"This is… a regional form?" Reiji stared at the panel, locked onto the Ice typing.
So its Water immunity wasn't because of the "regional form" at all. That had to be a separate bodily mutation—caused by eating those crystals in the cave.
Ice plus Ground could be compared to Piloswine: weak to Fighting, Steel, Fire, Water, and Grass… five weaknesses.
This combo wasn't normally immune to Water at all. If Crystal Onix truly was immune to Water-type attacks, that would cut one weakness away—leaving four.
Reiji liked the typing on paper, but if it evolved, the future looked bleak. Crystal Steelix—Ice plus Steel—was basically a prison sentence.
Ice/Steel meant a 4× weakness to Fighting, 2× to Ground, and a 4× weakness to Fire.
Sure, Water would be "covered," but it would pick up two nightmare matchups instead.
He'd suspected it earlier—either Crystal Onix was a mutation, or it was some kind of regional form.
That crystal body being immune to Water made sense as a special constitution, the same way his Shelmet had its own weird quirk—just in a different direction.
But he hadn't expected this one to be both: a regional-form difference plus a Water-immune crystal constitution. And he'd just ordered Poliwhirl to use Ice Punch… a little awkward.
This kind of change was probably something it ate its way into. And honestly, it wasn't without precedent—his Gastly had eaten its way into becoming Shiny too. Crystal Onix eating crystals until it gained an Ice type wasn't that unbelievable.
As for Terastallization?
No. This wasn't Terastallization. This Onix had simply mutated from eating crystals. It wasn't that complicated.
Truthfully, Terastallization felt like the production team running out of ideas and digging through older material for inspiration. There were plenty of examples.
Mega Evolution borrowed from Misty's old dream—she once dreamed of a "super" Gyarados.
Dynamax borrowed from the old giant Dragonite—Bill's Lighthouse, that enormous Dragonite.
Even the "different color regional forms" felt like another recycle. On Pinkan Island, Pokémon turned pink because they ate Berries. Crystal Onix was the same kind of deal.
The difference was that Berries only changed color. They didn't alter constitution. But Onix happened to be vulnerable to Water, and after eating crystals, its rocky body turned into a crystal body. Its Rock type even shifted into Ice—and it gained full immunity to Water damage.
That was why Reiji saw it as a regional-form difference stacked with Shiny, plus a special body that ignored Water-type moves. Crystal Onix was basically running two buffs at once.
And if you insisted on calling it "Terastallization," you could… but it was a stretch. The similarity was there, sure, and the production team had a track record.
Crystal Onix feared Fire, not Water. Terastallization could replicate that by changing type, but once it became Ice-type, it still feared Fire anyway. And once it evolved into Crystal Steelix, it would get bullied by two nightmare matchups.
Even if the Water weakness disappeared, Ice/Steel wasn't normally weak to Water in the first place. Immunity wasn't strictly necessary.
Still, neutral damage was still damage. Being completely immune to Water-type moves wasn't worthless. Otherwise, a Crystal Onix that hated water wouldn't be soaking its whole body in it.
But the more he looked at it, the less irresistible it felt.
If it evolved and got hard-countered by those nightmare matchups, he didn't want to raise a "nightmare matchup" of his own.
This Crystal Onix had Water immunity, 48% potential—barely acceptable—and an Advanced-tier level. It probably wasn't the same one from the anime with the sibling pair and their grandfather.
If it was that one, they'd be separated by at least fifty or sixty years. After eating crystals for that long, it wouldn't be this weak.
And its Ability and moves were ordinary too—basically just standard Onix move pool, nothing special.
All in all, aside from Water immunity, this Crystal Onix was pretty underwhelming. And its post-evolution typing was even worse.
It didn't feel like a "special" form at all. Reiji decided he'd just give it away.
To keep it like this, he'd probably have to keep feeding it crystals. If the crystals stopped, he suspected it might revert.
If it only ate crystals, he couldn't afford that kind of upkeep. The return didn't match the cost. Raising it made no sense.
Compared to that, Hanhan was Rock plus Ground. Hanhan wasn't afraid of Water or Grass, and its head was absurdly tough. No matter how he looked at it, raising Hanhan was the better deal.
With his mind made up, Reiji was ready to put the Poké Ball away, call his Pokémon, and head back.
Then a shout came from far to near, stopping him just as he was about to leave.
"Hey, friend over there! The Crystal Onix you caught—can you give it to me?"
[End of chapter]
[100 Power Stones = Extra Chapter]
[Check out my Patreon to read 20+ chapters ahead]
[[email protected]/BellAshelia]
[Thanks for your support!]