(Your party is a 3/3 red Fighter with first strike, a 1/1 white Cleric with lifelink, a 2/2 black Rogue with hexproof, and a 1/1 blue Wizard with flying.) How much does Dungeon Master cost
Each of these doubles something for you - be it damage, tokens generated, proliferate triggers, dying triggers or even just the power of your creatures - and each of them can also become indestructible by sacrificing something else
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
If they do, you draw a card and flip Prowl into Prowl, Pursuit Vehicle, which buffs itself with +1/+1 counters when other creatures or vehicles enter your battlefield
It also contains lots of cards that never get played in the same decks at all and are really hard to compare in many ways beyond abstract power and amount played