2-MV rocks are a pillar of modern EDH, and even most casual Commander bracket 1 decks should look to play a handful of these if they want to remain somewhat playable
If a creature's power is less than 0 when it's doubled, instead that creature gets -X/-0, where X is how much less than 0 its power is
But at the end of the day, this also makes it so that you can get cascade by doing damage through means other than commander damage
WotC has a special design team called Play Design, which is mainly responsible for playtesting MTG formats, including Limited and Constructed (mainly Standard)
Its a decent cantrip on its own thats card-neutral and offers some decent selection
This card can counter all other spells, switch each creatures power and toughness until the end of the turn, or make all creatures unblockable until the end of the turn