Few cards in Magic offer a multiplicative effect like Cathar's Crusade
If a Treasure you control is already a creature when Vihaan's second ability resolves and you choose to apply its effect to all Treasures you control, that effect will overwrite any previous effects that set that creature's power and toughness to specific numbers
Mega Gardevoir ex All For One Mega Gardevoir makes an incredible splash as the most iconic and impressive SIR in Mega Evolution, thanks to the quartet of Pokemon featured in the artwork, including Mega Gardevoir, regular Gardevoir, Kirlia, and Ralts, with the entire evolution line swirling in the center
I dont know if its too slow to impact Standard or not, but this will for sure murder people in EDH
Of course we will get this exact same rule over here too at some point, but there is currently no official word from Play