It's evolved over the years and recently we've had Gandalf the White from The Lord of the Rings
Some cards are human characters, some are objects like a Pokball or a healing potion
You could ask: Are you going to attack me this turn? Do you have a counterspell in your hand? Are you able to win the game this turn? If I were to ask you if you concede the game, would your answer to that question be the same as the answer to this question? Spark Fiend is hilarious because its not entirely clear what the card does, why it does it, or how it does it
It gives your rogues a power boost once graveyards fill up and helps mill opponents every time your squad attacks
This plays into another mechanic, which is this cards V Ability
Things like The Scarab God, Hashaton, Scarab's Fist, or even something like Altered Ego get the job done