Hmmm, that's an interesting problem. I see what you mean though. Because it is a solo challenge, I really don't want you fighting Agatha with other Pokemon, since to beat her, you would have to have them leveled to like 50 at least. So, I will allow the following...
Because he can learn the move in later generations, I will allow you to hack in the move Earthquake against Agatha. Sound fair? He learns it for sure in Gen IV, don't know about III.
Problem 2: It isn't the same for every single challenge, but for almost all of the main ones (solos and monotypes included) the endpoint is the second time through the Elite Four (first time you fight Alder or whatever his name is).
Because he can learn the move in later generations, I will allow you to hack in the move Earthquake against Agatha. Sound fair? He learns it for sure in Gen IV, don't know about III.
Problem 2: It isn't the same for every single challenge, but for almost all of the main ones (solos and monotypes included) the endpoint is the second time through the Elite Four (first time you fight Alder or whatever his name is).