Chapter 10: Challenge, the Power to Shake Rock!

Hearing its master's command, Onix, which had been coiled up, straightened its body. 

It raised its head, arching its long body like a drawn bow. Then, a thunderous sound erupted, and the seemingly cumbersome Onix charged towards the yellow mouse below with astonishing speed.

No one can remain calm facing a charging rock train, and Pikachu was no exception. The electric sacs on its cheeks sparked with golden arcs due to panic, and it quickly ran away from its spot on all fours.

Although its aura was intimidating, Onix was clearly no match for Pikachu in terms of speed. It slammed headfirst into the empty rocky ground, instantly creating a large hole.

And Brock's commands weren't over—

"Now, Onix, use Dig!"

Pikachu's electric sacs gathered sparks, clearly intending to launch a surprise attack while the opponent's move missed. 

But hearing the command, Onix didn't even look back and continued to burrow into the large hole it had created. 

In an instant, half of its body had already disappeared into the ground.

"Pikachu, use Quick Attack to stop it!"

Ash's reaction was quite fast. 

Knowing that other moves wouldn't be able to catch up with Onix's digging speed, he immediately gave the most suitable command.

Seeing Pikachu's body glow white in the field, it transformed into a white lightning bolt in the blink of an eye, striking the Onix that had not yet fully escaped underground.

"Good job, Pikachu!" Ash shouted excitedly.

But this excitement lasted less than a second. 

Onix's body didn't even pause for a moment from the impact of Quick Attack, and it burrowed straight into the ground. Instead, Pikachu was sent flying by the recoil, bouncing elastically on the ground a few times.

"Onix's defense isn't something Pikachu can shake." Kazuki glanced at the stunned Ash. The opponent had already made a huge mistake with his initial choice of Pokémon, and the resulting disadvantage couldn't be overcome with a little cleverness.

And, as expected, it knows Dig...

His gaze returned to the battlefield. Pikachu looked around uneasily, unsure when and from which direction the enemy that had disappeared from the field would attack.

"Dig is a Ground-type move, and it's super effective against Electric-type Pikachu. If it gets hit by this move, the battle might be over immediately."

Ultimately, he couldn't just stand by and watch. Kazuki sighed and reminded Ash beside him.

Waking up from his daze, Ash dared not hesitate any longer and shouted urgently, "Run, Pikachu! Don't let it find your position!"

Ash's idea was simple. Onix was now underground, and its eyes naturally couldn't see Pikachu on the ground. As long as it didn't stay in one place, it would be difficult for Onix to hit its target accurately.

But... Kazuki frowned. Pokémon like Onix were very sensitive to vibrations on the ground, especially in a familiar environment like this. Even without sight, the slight vibrations caused by Pikachu's movement on the ground would be enough to help it lock onto its target.

Before he could give another warning, the situation on the field had already changed dramatically—

Pikachu, who was moving at high speed, suddenly felt a violent shaking under its feet, almost losing its balance. Before it could react to what had happened, the ground beneath it cracked, and the rock snake burst out from underground.

"Pika!"

The violent impact made Pikachu's cute little face contort. The power of the earth permeated its body, and in its extreme pain, it could no longer make any resistance.

"Onix, Bind."

Pikachu fell helplessly in the air in a free fall. Waiting for it on the ground was Onix's thick body. The rocks coiled around the yellow body and then began to tighten.

"Pikachu!"

Ash clenched his fists, his expression struggling. Pikachu was showing a painful expression under the increasingly tight binding. As its master, he naturally couldn't bear to see this situation, but at the same time, he wasn't willing to give up just like that.

When he finally couldn't take it anymore and wanted to stop the battle, someone spoke up before him:

"Stop, Onix!"

It was Brock! Ash looked at the opponent in surprise. The Onix on the field obeyed the command without any hesitation, opening its body and letting the nearly suffocated Pikachu finally fall to the ground.

Without caring about anything else, Ash rushed into the field and picked up the weakened Pikachu.

"You should understand now, with your current strength, you can't possibly defeat my Onix."

Without the condescending tone of a victor, Brock simply looked at the challenger below and said, more like a reminder than a taunt.

Ash's defeat was a certainty built upon multiple mistakes. He still needed to grow... both his Pokémon and Ash himself as a Trainer.

He didn't know if he had listened... Brock looked at the figure leaving the gym and running towards the Pokémon Center, shook his head, and turned his attention to the other "challenger."

"My Onix didn't take much damage in the previous battle and can continue fighting... So, will you take his place and continue the challenge?"

"Oh, I don't..."

"Ko~ko!"

A metallic whimper interrupted Kazuki's intended refusal. He stared blankly ahead. Aron had jumped onto the rocky field at some point, its azure eyes burning with fighting spirit.

"It seems your Pokémon can't wait any longer. So... Are you ready to begin?"

"Uh, please wait a moment."

Kazuki jogged to Aron's side, bent down, and intended to persuade it to give up this gym challenge. 

However... when he looked into the flames burning beneath that azure, the words he originally wanted to say retreated back into his throat, reforming into completely different words:

"Onix is a Rock/Ground-type Pokémon. Rock-type is weak to Steel-type, so your Iron Head can deal effective damage to it. But the Ground-type move Dig is also super effective against you. Therefore, the ultimate victor will likely be the one who hits the opponent first..."

Onix uses vibration to judge the enemy's position. To avoid this move, it's best to have a move that can briefly float in the air. No contact with the ground means no vibration, but Aron doesn't have such a move... Wait, vibration?

"Have you finished discussing? It's about time to start."

Brock's voice came from the opposite platform. He had plenty of patience, but as a Gym Leader, it wasn't appropriate to let the challenger who had already entered the field endlessly discuss tactics.

"Yes, please begin."

Returning to his command platform, Kazuki took a deep breath, waiting for Brock's move.

That silver-white Pokémon... I've never seen it before. But with that armor covering its entire body, does it have Steel typing?

With a rough idea in mind, Brock waved his hand forward, announcing the start of the challenge. And the moment he made this gesture, the command from the opposite side had already been transmitted—

"Aron, Iron Head!"

As expected! His initial prediction was verified. Brock didn't hesitate at all and ordered in a deep voice, "Onix, use Dig quickly!"

As in the previous round, Onix slammed its head into the rock below, its entire body quickly burrowing into the hole it created.

A loud explosion rang out. Aron's Iron Head shattered a rocky outcrop, and the flying rock fragments even splashed onto the ceiling. The silver head shook vigorously, shaking off the gravel on its body. Its azure eyes, however, were not satisfied with the damage it had caused.

Brock, looking at the hole behind Aron's tail, subconsciously wiped the sweat from his forehead. He had underestimated this little guy's explosive power. 

If he hadn't given the order in time, Onix would have had a hard time avoiding that attack.

That's good, completely different level from that hothead just now. But from now on, offense and defense will change.

No matter how strong that Pokémon's destructive power is, it can't hit Onix underground. 

And in contrast, the Dig attack can deal heavy damage to Steel-type Pokémon. 

The opponent doesn't seem to have Grass or Bug typing, which can negate the super-effective damage... That is to say, Onix wins!

A confident smile appeared on Brock's face as he looked at his opponent. 

Somewhat surprisingly, the black-haired boy's face showed no signs of anxiety or panic. He even had his eyes closed, completely ignoring the situation on the field. What was he doing?

Vibration... Not only does walking on the ground produce vibrations, but Onix's movement underground should also produce even greater vibrations. When Kazuki closed his eyes, he could better sense the subtle touch transmitted from his feet.

It stopped.

Sensing the cessation of the vibration, Kazuki suddenly opened his eyes. 

There was only one reason why Onix would stop moving – that was the moment it was preparing to launch an attack!

"Aron, now!"

In Brock's astonished gaze, the long-awaited Aron opened its mouth, and then... spat out a rock.

The moment the rock hit the ground, Brock suddenly understood the opponent's purpose. He shouted urgently, "Onix! Wait..."

Unfortunately, he was too late. 

At the spot where the rock landed, the ground cracked open, and something huge was about to burst out from underground. 

Ground-type energy overflowed from the fissure. If it directly hit Aron, the super-effective damage might be too much to handle. However, Aron was now located at the edge of the fissure.

Pushing off with all four legs, Aron leaped into the air. The aftershock of the earth impacted its body, but because the power was too small, it only felt uncomfortable. Instead, the impact helped it leap higher into the sky.

"Now, use Iron Head again!"

Aron in the air responded with a cry. Its silver head glowed white, and it fell headfirst from the sky like a meteor. Under the force of gravity, the unstoppable Iron Head aimed directly at the Onix that was trying to escape back underground.

But it was too late... Under the watchful eyes of both trainers, two heads, one large and one small, one rock and one steel, collided at this moment!