They deserve this spot because theyre the easiest of all edict effects to exploit
Implementing the ante rules during these events would mean having to comply with various gambling laws, including getting gambling licenses and following other regulations
Similarly, a [X] cost becomes "Reduce enchanted creature's toughness by X." You can't pay a cost that would reduce enchanted creature's toughness to less than 0
Mega Mewtwo Y Mega Mewtwo Y, triggered by Mewtwonite Y, goes in the opposite direction entirely
However, these contributed to a high-power and thrilling metagame that elevated the rest of the game with it
March of Swirling Mist is the weakest of these because its constrained by mana or cards, but the fact that the spell actually does something itself, answering things like Collector Ouphe or protecting your creatures, makes it good enough to play