Corrupted Roots

In Commander, Corrupted Roots is a stax piece aimed squarely at the two most mana-efficient colors in the format — green ramp and blue countermagic — which makes it a real threat in the right shell, though the nonbasic-heavy nature of most high-powered pods blunts it significantly. Legacy and Vintage both have access to it, but those formats run so few basic Forests and Islands that Corrupted Roots rarely lines up against more than one land per game, making it a near-nonstarter. Modern is where it has the most competitive plausibility, since basic lands see more play and mono-green Tron or blue tempo decks can be genuinely set back by losing mana on every activation. Oathbreaker, like Commander, rewards it in dedicated hate builds targeting green-heavy or blue-heavy opponents.