Adding board pressure lets you kill your opponents fast enough to make use of those resources and overwhelm them, or you can outvalue your opponents with the built-in flicker synergy
Enter-the-battlefield decks especially love it when their engines fire off multiple times for extra control or value
I wouldn't include any of these cards in a deck just to deal with enchantments (I'd play Liliana for, well, general awesomeness, though)
Edgar Markov Look, I know Edgar Markov tops pretty much every best vampires list ever, and it's probably Magic's best Mardu card, but its easy to see why
Depending on the type, each set will normally have its own theme, either based around a particular fictional setting in the lore, or perhaps tailored to one particular mode of play, like the Commander or Modern formats
These types of cards give you more flexibility to dealing with threats at the cost of some stability