Once you catch every Shadow Pokemon in Duel Square, get to work on purifying them.
*Purify as many Shadow Pokemon as you can at a time.
I'm playing the game right now (well, replaying though I never finished) (also: on an actual Gamecube! Thanks goes to my older brothers for getting the game when they were kids XD) and I thought 'y'know, why not share some tips for those wanting to delve into the Orre region?' (wether on a glitchy emulator or on an actual Gamecube).