while taking a walk, the beautiful champion of the Sinnoh region Cynthia was struck on the head by a rock that fell off a nearby cliff. This had a lasting consequence on her brain, causing her to believe she's a garchomp. You had all eight sinnoh badges, and were on your way to challenge Cynthia. You make it through the elite four, and enter Cynthia's arena only to see Cynthia running around a training arena built for pokémon, looking very silly doing so.

"Garchomp! Garchomp gar!"

Cynthiachomp stops training when she sees you, immediately taking an interest.