TARDIS Bay

Planechase cards occupy a strange rules corner: they are not spells anyone casts and not permanents anyone controls, but a shared background clause that rewrites everyone's turn while it sits face-up. This one hands a cascade grant to the active player, and only the active player: the first qualifying spell each of us casts on our own turn digs for something cheaper and free. That single-player restriction is what gives the plane its shape. Cascade favors whoever can convert the dug-up spell into tempo, so the plane doesn't level the field; it hands the roller's whole table a rotating engine that only whoever is currently untapped can use. Most planes tax combat, mana, or draws rather than passing out a keyword that peels cards off the top and buries the misses at the bottom, which makes this an unusual kind of static ability for the format. The chaos ability is the sharper half. Where a typical chaos trigger fires and lets the plane stay put, this one steals an artifact and then planeswalks in the same beat, so the reward arrives and the exit slams shut together. That timing is the wrinkle worth watching: you take the artifact, then chaos itself closes the cascade window before the next player's turn can benefit from the grant, and the die decides who was standing in the right place when the trap sprung. It is ancillary design for a format that runs on shared randomness, where the interesting question is never what a card does but whose turn it happens on.