Maelstrom Nexus

Cascade arrived as a cast trigger glued to individual cards: one keyword on one spell, one free dig when you played it. This enchantment generalizes that into a board state, attaching the trigger to whatever you cast first each turn, and that reframing is the entire design proposition. A card with cascade gives you a single dig once. This turns the keyword into a static engine that scales with the length of the game, rewarding a deck of expensive payoffs and cheap enablers. The trigger refreshes on the first spell of every turn, not just yours, so an instant cast during an opponent's turn pulls a cascade out of it too: the enchantment can begin paying out the very next turn after it resolves, never needing to survive a full cycle untouched. The five-color identity is the cost that buys the effect: a permanent demanding all five colors asks the manabase to do real work before the engine does anything. There is also a sequencing wrinkle the keyword text hides. Cascade exiles until it hits a nonland card costing less than the spell that triggered it, so the value of your free hit is bounded from above by what you cast first. Lead with a one-drop and you cascade into nothing meaningful; lead with your most expensive spell and you open the widest window, since everything cheaper is now legal. The engine rewards casting your biggest spell first, not your cheapest, inverting the usual instinct to develop a curve from the bottom up.