Exile target creature with mana value X or less
The most important part of Expressive Iteration, for me at least, is that it doesnt create unfun games of Magic
You can argue that mana is the most important resource in Magic, so getting more of it is one of the best game actions you can take
Finally, it comes to the Legion of Dusk vampires' turn, and there's a moment of awkwardness as Amalia's cautious companion Bartolom introduces them as simply "humble explorers from the Queen's Bay Company." Riiiight
And while theres no place for it in modern decks (if you really want to gain life per turn, there are better ways to do it), its an interesting bit of MTG history behind it so much so that Wizards reprinted it in the Brothers War: Retro Artifacts set
The surviving cards were rumored to have been either given out to Wizards of the Coast employees or pocketed