[Update #2]: All of Magic: The Gathering's future cross-over sets will be legal in every format.
[Update]: MTG Arena has banned the contentious Leyline of Resonance in best-of-one Standard!
As with all of the Alchemy mini-expansions, the freshly released Alchemy: Duskmourn has now arrived with 30 new cards to muck around with. The new cards not only slot in well with the horror, enchantment and manifest themes of the main set, but many of them also share creature types with Bloomburrow's critters which gives them a lot of flexibility.
Furthermore, I feel like this Alchemy set has been the most spot-on in terms of power level. Nothing really stands out as being particularly obnoxious to play against, and there's only one card I would consider somewhat mediocre, and that's a mythic! Everything else, from the creatures to the enchantments, I can easily see being played in some sort of deck. So whoever designed both these cards and Duskmourn itself, hats off as you did a great job!
But enough of my rambling! You can check out the full list of cards, all neatly sorted by color, over at the official website.
My personal favorite card from the set is the Solitary Study / Endless Corridor that you can see below. It might not be as splashy as Fear of Change that lets you play Momir in the middle of a match, but the Endless Corridor has some truly delectable flavor and a lot of potential to 'go off' like crazy in the mid to late game. I could be overrating it a bit as I do have a certain fondness for cards that do a lot yet achieve nothing, but throwing down an endless chain of rooms is a lot fun and for me that's good enough.
Whatever the future might hold for MTG Arena, I'll make sure to let you know once Wizards of the Coast announce anything new. Chances are, that's going to be some spoilers for the upcoming Foundations set at some point next week.