Teach Eevee mimic in FR/LG, transfer it to any Gen4 game then grab a ditto and a Charizard with Flare Blitz and Rage. Now enter a double battle and have Eevee mimic Transform, switch out Ditto with the Charizard and have Eevee transform into it. Have Eevee use Rage until you get the 'rage is building' message, now finish the battle with anything other than Rage Eevee should retain the Charizards moveset after the battle if you did it right. Use a fire stone on Eevee and you should now have your very own FlareBlitzeon.
