So in order to play a challenge mode, do I have to delete all my data? There's no way to store saves for multiple runs? I put a lot of time into my first run, and it'd be a shame to just erase it all. But I guess there isn't much more to get out of my run if there isn't going to be anything to do beyond beating the elite 4 and the champion.
Also, I don't know what the intention was with the game design, but I never saw any incentive to use pokemon that require berries other than oran. Pokemon that require different berries don't seem to be any stronger, and don't add anything special to make it worth not being able to use any berry you draw to summon any pokemon you draw. It's not like pokemon that only use oran are in short supply.
Especially egregious are the legendary pokemon. I've only gotten a Zapdos, but I assume that its requirement to only summon with enigma berries is something they all have in common. Zapdos is barely any stronger than other pokemon, and I can't imagine it ever being worth using, considering the limitation on enigma berries in your deck, not to mention how hard they are to find in the first place. It makes legendaries pretty worthless, unless there's something I'm missing.