To use this you have to start off with Treeko

Sceptile, Kyogre, Manectric, Tropius, Hariyama, Kecleon.

The reason that this is such a good team is because you have an electric, water, fighting, fire, and two grass (grass pokemon are the overall best type because they have the least amount of weekness's and alot more pokemon are weaker to grass pokemon than any other pokemon)Trust me if you get all of these pokemon to at least 65 you are garunteed to win against the elite four and any other hard challenges.