what are proxy mtg cards - High Quality MtG Proxy Six (Borderless) from Modern Horizons

The flashback on Memory Deluge isnt just free flashback value instead of looking at four cards, you get to look at seven

The front faces of transforming double-faced cards are marked with a triangle facing up on the top left

Worldpurge Worldpurge was a fixed Upheaval, though the resulting card may still be broken

it theoretically handles fewer creatures, but not many players have more than 13 creatures by the time a board wipe is necessary, and sacrificing permanents gets around indestructible

If 3 is chosen, then it can only be damaged, enchanted/equipped, blocked, or targeted by cards that have a mana value of 3