Aoki bent down and carefully picked up the petite Carbink. His eyes widened slightly in surprise as he gently placed the small Pokémon into the hollowed-out depression in the rocky terrain.
The tiny Carbink tilted its head in confusion at first, not understanding what Aoki intended. However, its puzzled expression soon transformed into one of realization as it began to feel an overwhelming surge of rock-type energy rising from beneath the ground, flooding into its small body with incredible intensity.
Standing nearby, Aoki's Aggron also sensed the massive wave of unfiltered rock energy permeating the air. With each breath the steel-type Pokémon took, it absorbed tremendous amounts of energy - far more than could be gained through normal training methods. Both Pokémon immediately understood Aoki's plan.
Originally, the energy reserves were meant to be shared between three Pokémon - Tyranitar, Aggron, and Carbink. However, when Pupitar had evolved into Tyranitar earlier, it had absorbed nearly all the available energy. Now, Aoki was compensating the other two by allowing them to tap into this powerful natural energy source.
While the concentration wasn't quite as potent as the specialized evolution stones they had used before, the sheer volume of energy available here was more than sufficient. Tyranitar's body was already saturated to capacity with energy it hadn't fully processed yet - absorbing more at this point would provide diminishing returns. But for Carbink and Aggron, this was a golden opportunity.
"Carbink," Aoki said gently but firmly, "you must understand your body is undergoing permanent changes. Don't use this energy to simply increase your power level. Instead, focus it on accelerating your mutation process. Only after completing your transformation will you be able to reach your full potential - both for yourself and for your entire colony." He made no attempt to hide the mutual benefits involved from the small Pokémon.
Hearing Aoki's explanation, Carbink nodded resolutely. It too was intensely curious about what form its mutation would ultimately take.
"Aggron," Aoki turned to the massive steel-type, "you and Carbink should both absorb energy here, but be careful not to take in too much too quickly. Compress and refine the energy as it enters your body. We can't afford to destabilize your carefully built foundation just for short-term gains."
The Aggron responded with a deep, rumbling acknowledgement before focusing intently on carefully absorbing and processing the swirling rock energy around them.
Seeing both Pokémon properly settled into their training, Aoki sat down nearby to monitor their progress. Through his scanning system, he could see Carbink's mutation percentage had already reached an advanced stage. Once all its blue diamond protrusions completed their transformation to pink, its physical form would begin changing as well.
During previous observations, Aoki had noticed the energy from this pool seemed to accelerate Carbink's mutation rate when absorbed. Now, the small Pokémon was gradually learning to control the speed of its own transformation - though it couldn't reverse the process, only regulate its pace. For their purposes, this control was more than sufficient.
Only Aoki knew what final form Carbink would take after completing its mutation. As he silently monitored the mutation percentage through his scanning system, he noted the subtle influence of Xerneas' Horn was still actively affecting the process.
...
Three days passed in what felt like an instant.
Aoki and his Pokémon remained in Tyranitar Valley throughout this period. During these days, Tyranitar had been training extensively with the valley's leader and other wild Tyranitar, learning specialized combat techniques perfected by the tribe over countless generations. Given Tyranitar's natural aptitude, it had absorbed these lessons remarkably well - though fully mastering them would require continued practice.
Meanwhile, Carbink and Aggron eventually emerged from their energy absorption session near the valley's edge. Even a Pokémon's body has its limits, and they had reached the maximum amount they could safely contain. Notably, all of Carbink's diamond protrusions had now turned a vibrant pink hue. Aoki mused that any fragments that broke off would likely be genuine pink diamonds - though he wondered idly if they'd taste any different from regular diamonds.
Aggron had spent its time performing intense physical training while weighted down by massive boulders - essentially doing deep squats under tremendous weight. It wasn't alone in this regimen; Tyranitar joined the exercise, as both needed to physically process the enormous amounts of rock energy they'd absorbed. At level 58 and 56 respectively, they'd reached temporary plateaus - further growth would require time and disciplined training rather than sudden energy influxes.
Aoki realized his rock-type team had essentially maximized their gains from this location. Unless they explored deeper into the mysterious space below, there was little more to be gained here.
...
As if responding to Aoki's thoughts, a spatial rift suddenly appeared nearby. Strangely, Aoki had somehow anticipated Celebi would retrieve them around this time. Calling his Pokémon together, he returned all but Slowking, Gengar, and Tyranitar to their Poké Balls.
Tyranitar had clearly prepared for this moment. After emotional farewells with the valley's leader and other Tyranitar, it approached Aoki with determined resolve. During their stay, Tyranitar hadn't just learned battle techniques - Aoki had also taught the wild Tyranitar various survival skills, like more efficient water usage and improved cooking methods.
"Finished saying your goodbyes?" Aoki asked gently, noting the mixed emotions on Tyranitar's face. When Tyranitar nodded, any lingering hesitation in its eyes had been replaced by pure determination. Aoki gave an encouraging pat to Tyranitar's arm - as the King of Sandstorms, it should return to the proper world with this same confident bearing.
With Slowking at his side and Gengar hidden in shadows, Aoki stepped through the spatial rift. Behind him, the opening sealed shut like a zipper closing. Before he could even assess his surroundings, Celebi came zipping through the air before him, radiating palpable excitement as if demanding praise.
Aoki wasn't entirely sure why Celebi had taken such a liking to him - perhaps due to residual energies from Lugia or Mew, or maybe due to some intersection in alternate timelines. Regardless, he'd certainly benefited greatly from their association. "Thank you, Celebi," he said sincerely.
The mythical Pokémon twirled joyfully in response before waving its small hands to open two additional rifts. Moments later, Steven and Phoebe came tumbling out - both looking considerably worse for wear.
Steven's normally impeccable suit was torn and dust-covered, while Phoebe sported several visible scratches on her arms along with a general coating of grime. Despite their disheveled appearances, both Trainers' eyes shone with satisfaction - clearly their trials had been worthwhile. Steven was accompanied by his Metagross, while Phoebe's Banette hovered nearby - both Pokémon radiating significantly stronger auras than before.