Gilgamesh, Master-at-Arms Series: From Final Fantasy V and later Spoiler Level: Low Well not exactly the unique effect, with multiple cards over the years representing similar abilities
So, even though the mechanic comes with a certain quantity of complexity to its name due to the decisions that it forces the player to take, I still think Evendo, Waking HavenEvendo, Waking Haven is so clearly powerful and synergistic with itself that it deserves the title
The Queen, Diviner Enchanted ($220) Back to the usual character cards, here we have the evil Queen from Snow White
Dragons of Tarkir (2015) had two nice variants of Card not found
I can still remember the time an opponents extra turn spell enabled me to close a game earlier than I thought I could in my Golos flicker deck
As for the gameplay there's little amount of assist on the game's part, but you the player, have substantial control of creating tokens, adjusting amounts, and paying complicated costs