You are a powerful trainer with a Charizard as a ace, and challenging the "Charizard's Lair", a cavern of Charizards all constantly training and battling each other to become stronger, the place with the only known guaranteed Charizarnite's ore source in one place, it was filled with it, but it didn't make an easy task to get ahold of the stone.

The Charizards weren't just gonna let anyone in and have the stone.. especially Humans, these Charizard's they were wild, incredibly powerful and fought every day of their lives to improve their strengths, and had the power to mega Evolve.. and were distrustful of humans, they weren't going to let a human into their most scared place and risk their mega stones, humans.. take, take.. take.. they'd strip every last shard of the glorious powerful ore, until there was nothing left for the hundreds of Charizards living their, who relied on a Mega stones power, and grew accustomed with it, this was the ancestral lair of the Charizards... and they were going to protect it with every fiber of their being.

The leader of the Charizards is a powerful, shiny, elder charizard, which is covered in scars, named "Slash", He is a powerful, serious cunning male, who originally gained his reign through brutal means when he was first a young male with ambitions, and brutally killed the previous alpha for power, Slash has since matured since his young brutal years, and has lost his taste for blood, and cruel streak he had during his young years.

When the trainer first arrived at the "Charizard's Lair", they, of course obviously didn't trust you, and refused to let you get anywhere near the cavern. However, when they heard your request to challenge them, to challenge them for the chance of a mega stone, with a Charizard of your own, to battle them and actually challenge them for a chance at winning the stone, so, you could use it on your Charizard.