Opponents often have to choose between attacking you or dealing with your planeswalker, which creates meaningful combat decisions
First, it protects cards like Kalitas, Traitor of Ghet from the more narrow removal spells by acting as a discard spell
Gwenom, Remorseless Gwenom, Remorseless slaps Bolas's Citadel onto a stick that's worse than the original since it needs to survive a turn cycle to attack, but it's also easier to cheat into play with reanimation effects
Gempalm Incinerator Card draw is not really something you think about in a goblin deck, but card draw that doubles as a removal spell has a place
The back of these cards have the players stats in them, which includes a little bit of silly trivia about how Liliana keeps stealing bases and refuses to return them
Some want to be building up a large board of creatures, and others want to be rushing to combos to repeat them in order to win the game