Spire Serpent

The metalcraft mechanic almost always sweetened a creature's body or handed it a keyword; this one uses the same condition to flip its own role entirely. Out of the gate it is a 3/5 wall, a piece of board insurance that does nothing but sit in the way. Assemble three artifacts and the same body becomes a 5/7 that can attack, turning a defensive investment into a clock without changing a card. That conditional offense is the whole pitch: the defender clause is real text, not vestigial, and the deck has to actually hold up its end of the metalcraft bargain before the serpent earns its way across the red zone. The design reads as a deliberate bet on how saturated an artifact-heavy deck would be with permanents that count toward the threshold, betting that three artifacts is a floor those decks clear by default rather than a hoop they jump through. The honesty in it is that when metalcraft slips (an artifact traded away, a board wipe), the serpent reverts to a wall mid-game, so the body's offensive ceiling is only ever as stable as the artifact count beneath it.