These first five discussed will be the ally color pairs: White/Blue, Blue/Black, Black/Red, Red/Green, and Green/White
Shiny Museum 2 Shiny Museum 2 tasks you with finding five cards, but don't be fooled, they are all Shiny Mega EX Cards which can take a significant amount of time and luck to pull
This criterion is labeled in the To Solve portion of the Case
[0]: Untap target artifact or creature
Even among the remaining 70%, they showed little white spots on the bottom corners
Just like how those clamouring for Hogaak, Arisen Necropolis or Faithless Looting to get banned in Modern a couple of months ago should have been registering the deck all along, if you want to win and genuinely believe a card needs banning in Pioneer, then you should be playing it and trying to break it