The permanent with the ability needs to be on the battlefield to see you spend the mana
After sideboarding, you can change what the game is about, abandoning your low-impact creatures that would get caught in sweepers and instead presenting a midrange deck similar to theirs, but with counters and Eldrazi, and surprise them with a plan of going over the top of them without overcommitting to the battlefield
Its also great for pinging off utility creatures with one toughness, like Birds of Paradise
Whenever a Djinn or Efreet enters, destroy it
The Lord of the Rings: Tales of Middle-earth Riders of Rohan Commander Deck set includes 1 ready-to-play Blue-Red-White deck of 100 Magic cards (2 Traditional Foil Legendary Creature cards, 98 nonfoil cards), a 2-card Collector Booster Sample Pack (contains 1 Traditional Foil or nonfoil special treatment card of rarity Rare or higher and 1 Traditional Foil special treatment Common or Uncommon card), 1 foil-etched Display Commander (a thick cardstock copy of the commander card with foil etched into the cards border and art), 10 double-sided tokens, 1 Helper card, 1 deck box (can hold 100 sleeved cards), 1 Life Wheel, 1 strategy insert, and 1 reference card
It can even do so for a single mana and a few cards from your hand, making it incredibly versatile