Creature - Sphinx Crystalline Giant At the beginning of combat on your turn, choose a kind of counter at random that this creature doesn't have on it from among flying, first strike, deathtouch, hexproof, lifelink, menace, reach, trample, vigilance, and +1/+1
detail, detail, detail
1 Ancestral Recall 1 Black Lotus 1 Bolas's Citadel 1 Brainstorm 1 Chain of Vapor 1 Demonic Tutor 1 Flooded Strand 4 Flow State 2 Flusterstorm 2 Force of Negation 4 Force of Will 1 Gitaxian Probe 2 Hexing Squelcher 1 Hullbreacher 2 Island 4 Lrien Revealed 1 Mana Crypt 1 Manifold Key 1 Mental Misstep 1 Misty Rainforest 1 Mox Emerald 1 Mox Jet 1 Mox Pearl 1 Mox Ruby 1 Mox Sapphire 1 Mystical Tutor 1 Polluted Delta 1 Scalding Tarn 1 Sol Ring 4 Stock Up 1 Thundering Falls 1 Time Vault 1 Time Walk 1 Timetwister 1 Tinker 1 Tolarian Academy 2 Underground Sea 1 Urza's Saga 1 Vampiric Tutor 1 Vexing Bauble 2 Volcanic Island 1 Yawgmoth's Will 2 Abrade 1 Dismember 2 Hullbreacher 1 Hurkyl's Recall 3 Leyline of the Void 1 Long Goodbye 1 Opposition Agent 1 Portal to Phyrexia 2 Pyroblast 1 Yixlid Jailer The pillars of the format exist and are strong, but there's still a lot of room for customization among them

In case youre wondering how this blue creature works, it synergizes with spells that create copies, as those are one of the only ways to have spells on the stack that werent cast
If you look at Plume Fossil, youll see exactly how you can get Archen into play
Honorable Mention: Morophon, the Boundless Any time a typal group gets big enough to build a deck around, Morophon, the Boundless becomes an option to lead that deck