It's not often that we get a card that doesn't impact Standard much, but has a noticeable impact in older formats. When we do, it's usually some weird combo or interaction that the designers never planned for.
Madcap Experiment from Kaladesh fits that bill perfectly. It's a "Johnny" card (combo-centric) that opens the door to many Modern decks, and we've seen it slot into number of them in recent weeks. It's a fun package of 6-7 cards that can fit into any blue-red deck, and thanks to the wonders of mixing Magic cards from years apart, it often comes with little to no drawback.
Most commonly seen alongside Madcap Experiment has been Platinum Emperion. Thanks to the ability on the artifact creature, your life total never even changes by the time the Experiment gets around to that part of its resolution. Even if your opponent removes the Emperion, you're no worse off than when you started, which makes the combo no worse than a one-for-one in most circumstances. It's a powerful interaction that I think will make its way in and out of Modern for years to come.
But as solid as that line is, we can do better. Or, at least, more fun.
Platinum Angel has been around for a long time, and it's been a casual favorite that entire time. It's seen some play in Mono-Blue Tron in Modern before, but it's absolutely at its best here. With the ability to guarantee a Platinum Angel on demand – and as early as Turn 2 – we get to play the full set of Pact of Negation. Normally the free Counterspell is risky, but when we plan on using it to protect Platinum Angel we get to completely ignore the "lose the game" clause, meaning it's truly just a free Counterspell, and one we can flash back with Snapcaster Mage.
Blood Moon is the final piece of the puzzle. Not only does it provide some amount of free wins by locking out opponents, at the least it prevents them from easily having the colors they need to remove your Platinum Angel. Blood Moon is a cornerstone of these blue-red decks, and it absolutely does work here.
Round out the deck with the usual Counterspells, evasive threats and removal, and you have Madcap Moon.
Thanks for reading,