Shifting Shadows unique polymorph effect wasnt reprinted until Neon Dynasty Commander
After beating the game I admit I used Gameshark to get more promo Mew (the one that does 40 damage for two energies) and Mewtwo (the other "Do the Wave" attacker) cards to make a stupidly cheap deck
Each has flash or an immediate effect on entry: You can exile a creature (Solitude), strip a key card from an opponents hand (Grief), clear the board (Fury), disrupt spells (Subtlety), or wipe a graveyard (Endurance)
Here are the details of Hearthstones system with Magics rarity equivalent for comparison: Its a pretty straightforward concept
Twice Upon a Time is a sorcery with another sorcery attached, which opens up a new avenue for adventure spells to take
In conjunction with the Area Zero Underdepths stadium, this card can deal 240 damage, which makes it strong enough to deal with Raging Bolt without needing tools like Defiance Band or Maximum Belt