Mana Maze

A sequencing puzzle dressed up as a soft lock. Rather than taxing or countering, it keys off the color of whatever spell was cast most recently this turn and bars everyone from casting anything that shares a color with it. The mechanism is a static ability, not a trigger: it continuously checks the game state, so the restriction snaps into place the moment a spell hits the stack and applies even if that spell gets countered before it resolves. In a heavy mono-colored deck this is functionally a hard stop after the first spell: cast a blue spell, and nobody, including you, can cast another blue spell until a spell of a different color is cast. Multicolor cards complicate it further, since a gold card that shares any color with the last spell is locked out, which makes a two-color cast especially good at slamming a wider door. The design rewards a player who has engineered their own color sequence around the restriction while opponents, who did not plan their hand around it, choke on it: it is a prison piece that runs on asymmetry of preparation rather than a symmetrical resource drain like an upkeep cost. Two wrinkles matter. The check tracks the last spell cast by anyone, so a well-timed cast on an opponent's turn can shut down their next play, and a colorless spell, sharing no color with anything, sidesteps the lock entirely. It asks you to treat color as a turn-by-turn currency, not a line on a manabase.