Just one Demonic Consultation or Tainted Pack along with Thassa's is an instant-win
Thus a card that dominated the formats it was legal in or has regular play in Modern or Legacy like Atarka's Command, Wild Cantor, Burning-Tree Emissary, Huntmaster of the Fells, Manamorphose, or Bloodbraid Elf, would still need to prove it's chops at the kitchen table
WotC paid for the print run, so even the scrap is theirs if they want it
Youre going to want to quest with this character since he can generate four lore by doing so
Theyll continue to not use the hand selection algorithm that is used in non-Traditional modes, and starting with this release constructed Traditional events will not allow the MTG Arena exclusive cards from the New Player Experience
Community Formats Formats like Canadian Highlander and Old School have their own communities and regulations on whats allowed, so its best to track down some of them for the details