This music is straight from Pokémon Rumble/Melee! Pokémon Scramble (乱戦！ポケモンスクランブル), released June 16, 2009 in Japan. I DID NO REMIXING; I merely edited it to loop.
When I first heard this in the game, I was totally surprised. This is one of the most epic music pieces I have ever heard. If you want to know, the song itself is actually a remix of the RGBY Wild Pokémon Battle music.
More Pokémon Rumble, PokéPark Wii, Arceus and the Jewel of Life, HG/SS: