The Return of Greninja

A Mysterious Pokemon

Ash Ketchum stared blankly out the window as his partner, Pikachu, slept on his desk. He was sitting in class at the regional school in Alola. The lesson of the day was on mega evolution, so he wasn't paying attention. As he was about to drift off to sleep, he heard Professor Kukui calling his name.
"Ash! Since you seem to be paying attention so well, why don't you give me a summary of today's lesson?" the professor asked.
"Uh oh," Kiawe muttered from beside him. "You're in trouble now, Ash."
However, Ash just smiled. "Mega evolution is a circumstance in which a Pokemon that has reached its final evolutionary stage can take on a new form by use of a key stone and a mega stone. Each Pokemon has a specific mega stone meant for them," he replied promptly. "Some Pokemon, like Charizard, can have two mega evolved forms. But the transformation can only happen with the strongest possible bond between trainer and Pokemon. Mega evolution can also cause Pokemon to lose control sometimes, so it's important to make sure that your hearts are bonded as one."
Professor Kukui looked startled. Clearly he hadn't been expecting Ash to know anything about mega evolution. The other students in the class were looking at him with a mixture of surprise and awe.
"Well, that was an excellent summary, Ash. I'm glad to know you were paying attention after all," Professor Kukui said at last, recovering from his shock.
"Actually, I traveled through the Kalos region two years ago and learned a lot about mega evolution there," Ash corrected him. "Three of my rivals had Pokemon that could mega evolve-Trevor had Mega Charizard Y, Sawyer had Mega Sceptile, and Alain had Mega Charizard X. The Kalos Champion, Diantha, also had a Mega Gardevoir and Korrina, the Shalour gym leader, had a Mega Lucario like her grandfather."
"You met the Kalos champion?" Lillie gasped.
Ash nodded. "I battled her once, with my Greninja," he replied.
"Wow," Lillie breathed, looking at him in admiration.
"Do you have any Pokemon that can mega evolve, Ash?" Kiawe asked.
"I have Pokemon that are capable, but none that can actually do it," Ash said. Then he paused for a moment. "Well, Greninja and I could do something similar, but without the stones."
Kiawe blinked. "Okay, didn't see that coming. What do you mean by that?" he asked curiously.
"Greninja and I can use something called the bond phenomenon," Ash answered. "Basically, Greninja goes through a transformation of his own where his features change to look like me. During that time I can see and feel everything he does, which means that I feel pain whenever he gets hit."
"Where's Greninja now?" Mallow asked.
"Greninja had to stay behind in Kalos to protect the region from Team Flare. I haven't seen him in two years," Ash said, a sad note entering his voice.
"I'm sorry, Ash," Lillie said sympathetically.
"It's all right. His mission won't last forever," Ash said, smiling cheerfully now. "As soon as he's done, we'll meet up again and battle together."
Just then, they were interrupted by Officer Jenny entering the classroom. Professor Kukui immediately stood to greet her.
"Officer Jenny, is there something we can do for you?" he asked politely.
"There's been a report of a strange Pokemon at the beach. Everyone is being asked to help investigate in case it turns out to be a threat," Officer Jenny replied briskly.
Professor Kukui nodded and turned to the class. "You heard him, everyone. To the beach."
Ash shook Pikachu awake and let the electric mouse hop onto his shoulder before following his classmates out the door. The beach, which was located right outside the school, was already crowded with trainers and Pokemon alike by the time they arrived. Ash immediately split up from his classmates and began to search the beach.
"Does anyone know what this Pokemon looks like?" he asked a passing trainer.
"I think someone said it had two legs and was blue," the trainer told him.
Ash sighed to himself. That narrowed down the field, but there were still a lot of Pokemon that were blue and had two legs. If he could just find the person who had spotted the mysterious Pokemon, he could ask him or her what it had looked like. Unfortunately, he had no idea who had seen it. And finding a way to contact said person? Forget about it.
All right, let's think for a minute, Ash thought. I can eliminate any Pokemon that isn't blue or that doesn't walk on two legs. I doubt it's a Kanto Pokemon either, since all the Kanto Pokemon can be found in Alola too. Let's see, what Pokemon are blue and walk on two legs? Lucario's kind of blue, but I think everyone's seen a Lucario before. Wait a minute...no. It couldn't be...
Ash stopped in his tracks as a thought occurred to him. Was it possible that the mysterious Pokemon was his Greninja?