Hidden Strings

The tap-untap effect itself is small change: untap a land to fake counterspell mana, tap down a blocker, the kind of utility that rarely earns a card slot on its own. The whole pitch is the cipher rider. Encode this on an evasive creature and every connection casts a free copy, which means every turn it survives you get two free tap-or-untap effects in perpetuity. That repetition is what turns a marginal trick into an engine: untap two lands a turn for ramp, or tap two blockers a turn to clear the way for your next attack. The design lives or dies on delivery. Cipher asks you to land combat damage before the card does anything beyond its modest one-shot mode, so a spell that reads as filler in the abstract becomes a payoff measured entirely by how often you connect. This is cipher's central tension at its clearest: the mechanic prices a powerful repeatable effect against the cost of building a board that actually hits, stapling the encoded payoff to a creature's survival rather than to mana. Hidden Strings happens to pair that structure with an untap effect that wants to be abused, which is why it found a home in combo shells few would predict from reading the front half of the card alone.