I am fearful of Hogaak, Arisen Necropolis decks and other powerful graveyard strategies emerging in Modern, so I want to employ a full set of Leyline of the Void to give myself a fair shot in the post=sideboard games
Ward 3 is a hefty cost for any opponent, which means its much more likely to make it to a combat step
Reach, a mechanic introduced on Giant Spider and its many friends, was only keyworded after it existed on a couple dozen cards
You want to hit cards like Brimaz, big fat dorks that need to get into combat before they have done much, if you hit these kinds of card there is a good chance you won't see it played again, they will either be dead before they have the time or will have won anyway regardless of the Brimaz they have in hand
As much as you and your wallet may wish otherwise, there's nothing quite like a Maccies promo, and the new McDonald's cards are proof of that