Cain, sitting on Flygon's back, wasn't exactly idle.

Previously, he had obtained a Lucario training manual from the Tower of Mastery, which was completely recorded by his system.

What concerned Cain the most was how to restore the Riolu egg he had acquired.

After an entire night of analysis, the system finally found a method with a fairly high success rate.

As soon as he got the result, Cain extracted the procedure provided by the system.

According to the analysis, if the egg was to be restored without affecting its original potential or talent, it had to be done using a combination of materials containing aura power—as mentioned in the book—as well as a strong aura source for support, which could come from either humans or Pokémon.

The proper combination would allow the Riolu egg to be repaired, and if the materials were of high quality and the aura power strong enough, the Riolu born from it could potentially possess even greater talent.

Of course, such materials were far from easy to obtain.

Some of them had been documented long before the League was officially established in the Kalos region, and it's possible that their names have since been changed.

Moreover, materials that contain aura power are not exactly common.

But having a way to do it is always better than having no option at all. It was just a matter of searching slowly over time.

After all, there wasn't an immediate urgency for that Riolu, since Cain's current Pokémon lineup was already well-defined and in the process of training. Even if it hatched now, he wouldn't be able to devote much attention to it.

...

Soon, Flygon descended in front of a remote cave entrance.

This place was most likely part of the Connecting Cave.

However, it wasn't the main entrance.

As a vast underground network, the Connecting Cave had many entrances scattered across the terrain.

Currently, the caves hadn't been cleared by the League, so they were filled with wild Pokémon. In comparison, the surface routes were much more accessible.

But in the future, the League planned to assign a large number of personnel to clear the entire network, turning it into a shortcut much like Kanto's Diglett's Cave.

For now, not many people dared to enter.

Not only because of the number of wild Pokémon, but also because of the unbearable stench inside the caves.

But for Cain, none of that was a problem.

He called Blaziken, Pupitar, and Lairon, and headed straight into the Connecting Cave.

The moment he crossed the entrance, a foul stench hit him full force.

Blaziken and the others also grimaced in disgust.

Cain slightly frowned but didn't hesitate to continue. He held a torch designed specifically for cave exploration.

In his past life, when he had just arrived in the Pokémon world, he had lived in even harsher environments. Compared to that, this was nothing.

Besides, this smell was nowhere near as bad as that of a Muk or Grimer.

In the future, his Pokémon would have to face enemies with strong odors as well, like Vileplume or Skuntank. Smell shouldn't affect their combat performance.

After a while, the Pokémon got used to it.

Their physical constitution was far more resilient than that of humans, and their adaptability far exceeded any person's.

Before long, the sound of wings flapping en masse could be heard.

They were mostly Zubat, though there were also some Golbat.

These Poison/Flying-type Pokémon were weak against Rock, Ice, Electric, and Psychic moves.

Pupitar and Lairon's Rock-type moves could do considerable damage to them.

Additionally, Lairon's Steel typing made it immune to Zubat and Golbat's Poison-type moves.

As long as Blaziken kept his flames under control, there wasn't much to worry about.

As for Pupitar, his tough shell and energy control allowed him to form a thin but sturdy protective layer of combined Ground and Rock-type energy.

While Cain held the torch, Ralts swayed lightly on his shoulder, half-sitting and half-floating.

Being a Psychic-type, Ralts had the advantage against Poison-types.

Moreover, the Zubat they'd encountered so far were low level, giving Ralts space to act freely.

However, the number of Zubat was much greater than Cain had expected.

When he looked up, the ceiling of the cave was invisible; it was completely covered in Zubat.

Anyone with trypophobia would have a terrible time in this place.

Although Cain had mentally prepared for this scene, seeing it in reality still made him frown.

Not because it was difficult to handle so many Zubat, but for another reason.

With such a number of Zubat, and even a considerable amount of Golbat, a major question arose: where were they getting enough energy to survive?

There wasn't just enough energy to sustain them—it even seemed abundant, allowing them to evolve and grow stronger.

This sparked great curiosity in Cain.

Also, the League had ignored this area for a long time, despite having been present in Kalos for years.

Why had they only now decided to intervene in the Connecting Cave?

Had something in particular caught their attention?

After all, the place with the most experts in Kalos—outside of the League HQ—was precisely the Battle Chateau on Route 7.

Was it really that difficult to send people to clear this place?

Curiosity began to fill Cain's heart.

"Fight until you're exhausted," Cain ordered his Pokémon.

"Blaziken, this is the perfect place to improve your speed and dodging ability. Maximize your speed, then use Swords Dance."

"Pupitar, use Sandstorm! Turn the entire cave into your terrain!"

"Lairon, alternate between Rock Tomb and Rock Slide."

"Ralts, act as you see fit."

Under the sandstorm, all Pokémon that aren't Rock, Ground, or Steel-type take constant damage.

Blaziken too, of course, but the damage was minimal compared to what the Zubat would suffer.

Besides, Blaziken was meant to be part of both Cain's rain team and sandstorm team, so it was important for him to get used to that environment.

As long as Pupitar could control the storm well, the damage to Blaziken would be perfectly manageable.

Pupitar also carried the Smooth Rock, which boosted his ability to extend the sandstorm's duration.

Combined with his already excellent energy control, this was the best opportunity for everyone to get familiar with future battle strategies.

After thinking for a moment, Cain also summoned Carbink.

And just like that, half of the sandstorm team was complete.