>>55325653I’ll give you some actual answers here
>base game -> ChampionTeam doesn’t really matter, just use what you find to be cool and start working on your pokedex by catching everything you see
>100%Look into the trainer card stars, they’ll be what you need for 100% completion.
>>Enter Hall of FameEasiest one, completed just by playing the game
>>Master rank in contestsShould be doable, just have to learn how contests work
>>100 streak in battle towerAgain, should be doable, just try to find good team compositions on something like smogon forums
>>Platinum flag in undergroundNot 100% sure about this one, but I think you need another ds and another copy of one of the sinnoh games. You might be able to do this with a used DS Phat and a Japanese copy of diamond or pearl for really cheap
>>National dexAgain, you’ll need another ds for trades, but I think you need hgss and even gen 3 games (?) for the regis and dual cartridge exclusives which are expensive. Probably the most expensive/time consuming
Good luck
