The Mycosynth Gardens

The third ability is the reason this exists, and it inverts how a land usually behaves: instead of tapping for mana, it pays a variable cost to stop being a land and become a copy of a nontoken artifact you control whose mana value matches the X you spent. The size of that X is the whole design lever. On a cheap X it duplicates a mana rock or a small engine piece; on a large X it becomes a second copy of your marquee artifact, drawn out of nowhere and attached to a land drop. That copy effect is where lands of this kind quietly warp resource math, since it converts a spent land into a permanent that would otherwise cost real mana and a card. The two mana abilities keep it honest as a land in the meantime: it enters producing colorless immediately, filters into any color for a premium, and does ordinary land work until the artifact half of a deck matures enough to justify copying something. It commits to nothing up front: it is a land first, and only becomes a threat once you have a nontoken artifact worth cloning and the mana to clone it. The friction is that copying a large-value artifact ties up a full turn's mana on an ability that lands no immediate board impact of its own.