In truth, [Bond Evolution 2.0] was still far from the endpoint of Bond Evolution. One could even say that Greninja had yet to truly master the power of Bond Evolution.
Bond Evolution was a power meant to stand alongside Mega Evolution. Since it was an evolution, a change in appearance was one of its most fundamental characteristics, regardless of whether it was Mega Evolution or Bond Evolution.
However—
At present, when Greninja activated Bond Evolution, its body was merely enveloped in raging torrents of water. Its physical form itself had not undergone any changes whatsoever.
Although Ash had currently named Greninja's transformation Bond Evolution 2.0, if placed in the context of the original timeline, this was merely the stage that Greninja had reached when Ash and Greninja first awakened the power of Bond Evolution by accident.
In other words, Greninja's current Bond Evolution 2.0 would only be considered Version 1.0 in the original timeline. Moreover, whether it was the Greninja from the original timeline or Ash's current Greninja, there was still quite a long road left before they could truly master the power of Bond Evolution.
Therefore, Ash didn't allow himself even a moment of relaxation.
After completing Greninja's strength assessment, he immediately and enthusiastically led it into the third stage of training.
And the contents of this third stage had already been carefully planned out long ago.
The reason Greninja had been able to fulfill the requirements for Bond Evolution 2.0 during the previous stage of training was largely due to Aura Power's assistance. Without Aura Power's aid, there was no telling how long it would have taken Ash and Greninja to achieve complete unity of heart and mind.
Thus, the objective of the third stage of training was quite simple.
After arriving at the destination known as Bond Evolution 2.0, Ash and Greninja would turn around and walk back to retrace the final stretch of the journey—the portion they had taken a shortcut through—with their own strength, step by step.
They would cast aside their dependence upon Aura Power and fulfill the prerequisite condition for Bond Evolution through nothing but their own efforts.
That prerequisite was—
Complete unity between Trainer and Pokémon.
Since they had already achieved this condition once through Aura Power and had successfully undergone Bond Evolution 2.0, reaching that same destination again without Aura Power would be much easier this time around.
It was like voluntarily returning to repeat one's final year of high school after already having entered university. With prior experience and accumulated knowledge, repeating the journey would naturally be far less difficult.
More importantly, Ash wasn't planning to completely abandon Aura Power all at once.
Instead, he intended to gradually reduce its usage little by little until both he and Greninja could completely free themselves from relying upon it.
Throughout that process, Aura Power would still remain involved to some degree. Even if its influence gradually diminished, it would continue providing tremendous assistance and benefits to both Ash and Greninja's training—advantages that ordinary people simply couldn't hope to possess.
Especially since Ash wasn't planning to discard Aura Power in a single step, but rather slowly and steadily remove his dependence upon it.
And throughout that process, Aura Power would continue offering invaluable support—something beyond comparison for ordinary Trainers.
"Greninja, let's continue our training. Let's master the power of Bond Evolution as soon as possible."
After completing Greninja's strength assessment, Ash looked toward Greninja, who had already exited its Bond Evolution state, and spoke with a smile.
"Gren! (_)"
Greninja nodded before accepting an Oran Berry that Venusaur handed over from the side. It quickly devoured it to recover its stamina before turning back toward Ash and nodding once more.
The third stage of training officially began.
This time, they would still be conducting practical combat training, but their sparring partner had changed from Pikachu to Pidgeot.
...
High above the untamed grasslands beyond the riverbank, Pidgeot flew gracefully in low-altitude patrols like the undisputed ruler of the skies surveying its territory.
And as a mighty avian predator, patrolling its territory naturally went hand in hand with hunting for prey.
At this moment, Greninja had become the prey caught within Pidgeot's sights.
Whoosh! Whoosh! Whoosh! Whoosh!
With a single spread of its massive wings, countless razor-sharp blades of wind descended from above like an army of invisible assassins.
"Greninja, dodge!"
Seeing the incoming attack, Ash immediately issued an evasive command from the clearing below.
"Gren!"
Greninja's movements were extraordinarily agile. In fact, before Ash had even finished issuing his command, Greninja had already begun instinctively dodging.
The slicing wind blades descended violently from the sky. Yet Greninja moved as gracefully as a dancer performing amidst a storm of blades and arrows.
It was an absolutely breathtaking sight.
Despite the heart-stopping danger, Greninja successfully evaded Pidgeot's relentless assault.
CRASH! CRASH! CRASH!
The wind blades struck the ground, sending grass and dirt flying everywhere.
Yet against Greninja's nimble footwork, every one of Pidgeot's attacks struck nothing but empty space.
"Greninja, use Rain Dance!!"
Having endured Pidgeot's opening assault, Ash naturally had no intention of giving it another opportunity to seize the initiative. Without the slightest hesitation, he immediately issued a counterattack order.
"Gren!"
Greninja, who had been weaving left and right across the grasslands, performed a swift sliding step before suddenly planting its feet firmly upon the ground.
Gathering its power at its waist, it forcefully launched a mist-filled sphere of water vapor toward the heavens.
Drizzle... Drizzle...
The sphere exploded high above, and before long, a gentle rainfall began descending from the skies.
For Flying-type Pokémon—especially avian Pokémon—their wings were their greatest weakness. During battle, crippling an opponent's wings was often the quickest path to victory.
Of course, directly damaging an opponent's wings was far easier said than done.
When direct attacks proved ineffective, reducing their aerial mobility was often an exceptionally effective alternative.
Greninja's Rain Dance soaked Pidgeot's feathers with rainwater. As its feathers became heavier from moisture, its flight capabilities would naturally suffer considerably.
However, Pidgeot was one of Ash's meticulously cultivated ace Pokémon.
Naturally, Ash had long anticipated this weakness and prepared countermeasures for it.
Although Pidgeot currently lacked Ash's direct commands, it had already grown into a Pokémon capable of standing proudly on its own.
Faced with this situation, it displayed neither panic nor hesitation.
"Pidgeot—!!"
High in the skies, Pidgeot raised its head and released a clear and resonant cry.
At the same moment, it launched a brilliant golden sphere of light toward the heavens.
The golden sphere exploded.
Dazzling rays of scorching sunlight pierced through the rain clouds like countless golden swords, instantly transforming the previously gloomy skies into a magnificent tapestry of light and color.
Pidgeot had chosen to counter Rain Dance with Sunny Day.
Ash wasn't surprised in the slightest.
After all, Pidgeot was an ace Pokémon that he himself had painstakingly nurtured.
However, Greninja's proficiency with Rain Dance was exceptionally high. Even Sunny Day could only partially negate its effects.
The sky now existed in beautiful chaos—a world where sunlight and rainfall coexisted simultaneously.
One side basked beneath brilliant sunshine, while the other remained veiled by falling rain.
And for Ash, this result was already more than satisfactory.
He had achieved exactly what he wanted.
"Greninja, use Water Shuriken to force it to reposition!"
The moment Pidgeot finished using Sunny Day, Ash immediately issued his next command.
"Gren!"
Whoosh! Whoosh! Whoosh! Whoosh!
One Water Shuriken after another streaked across the battlefield.
Originally, Pidgeot had been hovering beneath an opening in the clouds where the rain couldn't reach it.
Yet faced with Greninja's relentless barrage of Water Shuriken, it was gradually forced back toward the surrounding rain clouds.
And eventually—
It was forced once more into the falling curtain of rain.