This Pikachu was a female. You could tell by the heart-shaped tip of her tail. Her gaze was fixed on you, her head still tilted to the side in confusion as she stared at the tiny human. Her ears twitched, and she sniffed the air. Admittedly, she looked adorable, but you were currently the size of a little toy compared to her. And you knew you’d be utterly helpless if she came over to you and got her paws on you. You had to do something. 
After staring at you for a bit, she grinned. “Pika!” she cried out. The yellow giantess took a step forward, then another, her pace quickening with each stride. Her face was lit with a mixture of curiosity and excitement. She was eager to come over and investigate the strange little human she’d found.
You took a nervous step back. A bead of sweat trickled down your temple as you reached for your Poke Balls. You’d considered trying to befriend this Pokemon moments ago, but the sight of the enormous rodent coming closer was terrifying, and you decided to fight instead. But what Pokemon would be best to use? Rather than relying on Dusknoir to status her, you felt like using a type advantage would be better here. You needed to hit Pikachu and fend her off, convincing her not to come any closer.
“Flygon, let’s go!” you yelled, tossing the ball forward. A flash of light erupted, and your beloved Dragon-type appeared once more. He looked around, and shuddered again as he saw he was still tiny. But he also gasped and took on a fighting stance as he saw the towering Pikachu coming closer.
Pikachu stopped once he appeared. She let out a questioning “Pi, pika?” as she looked from you to Flygon, as if wondering whether you were really going to take a risk and attack her.
You didn’t waste a second. “Flygon, use Earthquake!” The Pokemon hovered in the air for a moment, then stomped down with both feet. A small tremor rippled out from his position, kicking up dust and causing a few pebbles to rattle. Cracks appeared in the ground too, but they were small. Pikachu squeaked and stumbled a bit, but the shaking was really minor, and she recovered in seconds. Even a super-effective attack didn’t do anything. Flygon was just too tiny now.
You cursed under your breath. “Flygon, Dragon Claw! Let’s get her!” His wings started buzzing and he flew forward, his claws glowing with draconic energy.
The yellow giantess watched him, and let out a high-pitched giggle, as if amused by the tiny and weak Pokemon rushing at her. He tried to slash at her, but she swatted him away with her paw. Flygon recovered and tried again and again, but Pikachu was quicker. She kept hopping away from him and swatting him with her paws and tail, giggling and squeaking happily the entire time.
The young Pikachu was playful, treating the entire encounter like a game—but for Flygon, it was an intense fight against an enormous enemy. As you watched, you could tell this was hopeless. Your strong Pokemon had been weakened so much by Mew, and a mere Pikachu just saw his struggles as nothing more than playtime.