Tower of the Magistrate

The pinpoint answer to a problem most lands never bother addressing: equipment and artifact-based removal pointed at your best creature. For one generic mana plus the tap, you grant protection from artifacts, which strips off any attached Equipment, fizzles a targeted artifact burn or removal effect before it resolves, and renders an attacking or blocking creature untouchable by artifact sources. Protection covers the full suite (damage prevention, can't-be-enchanted-or-equipped, can't-be-blocked, can't-be-targeted), so it rescues a creature from an artifact-source attacker mid-combat as readily as it nullifies artifact removal aimed at it. The design holds together because of where the ability lives: this is a colorless source that also taps for mana, an emergency valve folded into your manabase rather than a deck slot you have to justify. You only spend on it when an artifact threat materializes; in the long stretches when none does, it quietly produces colorless and asks for nothing. The activation tax is what limits it. Because both the mana ability and the protection ability share the tap, you cannot draw mana off this source and shield a creature in the same window, so the protection is not free and not repeatable on a single turn. Narrow by construction, it is insurance printed onto a permanent that costs nothing until the matchup demands it.