Yshtola Rhul While Y'shtola Rhul is pretty costly, its also pretty unique: No other card gives you additional end steps, with which you can exploit powerful effects like Agent of Treachery and Primordial Mist
The sector, legal and illegal, is a long way from recovering
Most of the final bosses from the 16 main games are accounted for
Ancient Tomb + City of Traitors While Ancient Tomb is clearly superior to City of Traitors, most decks that include the former find room for a copy or two of the latter
There is always the concern that casting Wheel when everyone is low on cards can hand an opponent the removal spell, counterspell, or combo piece they desperately needed
There are nods to the video game as it looks like those delicious poffins players of Pokemon Diamond and Pearl spent hours making