yugioh reverse trap card may be 1st or Unlimited Edition Reverse of Reverse | Yu-Gi-Oh!

Tolaria West, Muddle the Mixture, and Dimir House Guard tend to be some of the more common transmute cards

Phyrexia's Core

First, you can abuse it by dropping it on Birds of Paradise or 1/1 tokens and such

Credit: Wizards of the Coast Stick Together is at least a bit more on theme and an interesting card, potentially quite good because it's a sacrifice effect as opposed to destroy, where you could dodge it by maintaining a party, but it feels like it's always going to hurt the deck a fair amount, counting on wrath + indestructible seems a lot more dependable, even if opponents creatures will occasionally also be able to dodge it

Since most of your spells require blue mana, don't counter creatures you can kill with Galvanic Blast as soon as they're in play, especially if they only have one or two toughness