Darksteel Reactor is indestructible. ("Destroy" effects and lethal damage don't destroy it.)
At the beginning of your upkeep, you may put a charge counter on Darksteel Reactor.
When Darksteel Reactor has twenty or more charge counters on it, you win the game.
Near Mint Condition
A card in Near Mint condition shows minimal to no wear from shuffling or general play. Cards classified as Near Mint/Mint are generally indistinguishable from cards in an unsleeved deck of other Near Mint/Mint cards. Foils in this condition have little or no scuffing or clouding on the front and edges of the card.