Darksteel Ingot

Most three-mana fixing rocks tap for one of any color and quietly die to the first artifact sweeper or shatter effect that comes along; the indestructible keyword strips that vulnerability out. This is fixing that shrugs off the removal that usually punishes a ramp-heavy opener: anything that says "destroy," from Vandalblast to Shatterstorm to a board-wide artifact wrath, simply leaves it untouched. The trade is durability for speed. It costs more than the Signet-tier rocks, it never accelerates you the way a two-mana option does, and it produces a single mana per turn rather than two. What you buy with that premium is a manabase the opponent cannot reach through their normal channels. It is less a turn-three accelerant than a permanent floor under your colors, the rock that survives to rebuild on the rubble of a wipe and keeps casting spells while everything else gets reset. That makes it one of the cleaner statements of what indestructibility is actually for: the keyword is most interesting not bolted to a finisher the opponent was always going to chump or exile, but to a supporting piece they fully expected to be able to remove. A fixing source that ignores the entire "destroy" half of the removal suite changes how an opponent has to spend their answers, and it does so on the least glamorous card on the board.