Since the story is pretty long, I put each section into spoilers. I also combined the idea of Pokemon and The Hunger Games. The intro is left open for an idea.
Warning: This is rated T or PG-13 for some language and minor violence.The Pokemon Games
There was a time Unova never existed until a thousand years ago. The two fierce dragon Pokémon, Zekrom and Reshiram, fought each other constantly and clashed as their trainers did too. The trainers were hailed as heroes because they woke the mighty gods with their beliefs of a new world- which came to be known as Unova by the winning hero and trainer of Reshiram. The trainer of Zekrom promised to take his revenge.
The hero came to be known as Black and he was a kind, gentle soul who – through Reshiram – created the new pokemon to run freely and become future friends of the humans who soon follow after their migration from other worlds. The people started their journey finding Pokémon, working their way to become leaders, and started families for the bloodline to continue in Unova. Black saw to everything and made sure the world flowed freely and protected by him and Reshiram.
The peace didn't last long though. The hero White and his dragon Zekrom returned stronger than ever. They immediately charged through the sky during a ceremony for Black and White attacked the stage and wounded a few civilians who ignored their burns to stare in fear. Black tried to back away from a fight when White got mildly aggressive with his own hands. It was no use however. Reshiram saw the abuse his trainer received and retaliated in response. Zekrom defended White and fought Reshiram while their trainers fought each other. The fighting ceased after some time, but White reminded Black he still wanted his revenge.
Black slowly became paranoid of a possible entrance from White or an assassination attempt. He couldn't focus straight on the world surrounding him and avoided those he believed were betraying him in secrecy. Reshiram tried to calm his nerves, but all the attempts were in vain. He shriveled after staying in the dark for a long time, but his childhood friends pulled him out into the light. Black trusted his best friend and came out only to find a strange Pokémon stab him in the heart. White had won.
The people of Unova did not trust their new leader. They were highly suspicious of White and his tyrannical ways against innocent people and Pokémon. White grew furious when people sic their Pokémon friends on the supporters and fought back until the civilians surrendered. As punishment, White created a battle arena where Pokémon fight to the death.
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