Depending on context, these cards may be called prison pieces, hate cards/hatebears, sideboard cards, or, in some circles, stax cards after the ancient Smokestack-based deck which popularized not letting the other person play as a strategic archetype
Just remember not to actually crew your Druid-mobile at any point, lest it instantly collapse under the weight of its trillion -1/-1 counters
TCGplayer has pre-built APIs available for use in your website/app, letting you use pricing data in a variety of ways
If the enemy pulls a Pokemon to the Bench because of Guard Press, use Leaf to get Hitmonlee out for the KO blow
Card draw is another reward, often connected to paying mana, like with Shanna, Purifying Blade, Well of Lost Dreams, or Dawn of Hope
The nature of land bases hasnt changed for Brawl compared to its Commander predecessor in that respect