The plane Astral Arena, for example, wont let players attack or block with more than one creature, and that effect is active regardless of the planar die roll
Its also in more EDH decks than Coat of Arms, Illusionists Bracers, Paradox Engine and Aetherflux Reservoir and a lot of those decks were registered before Crucible was affordable
Make S:P Little Knight with Gullveig and Ivaldi
Cards from The List appear in Set Boosters in the final card slot about 25% of the time
I might not have all the mechanics down, and Im still misreading what some spells do, but Magic: The Gathering Arena has this way of teaching you without discouraging you
Nihilengo is an excellent tech card for any deck that uses Poison to bring down their opponents