Mystic Remora is cheaper and costs significantly more mana from the opponent to prevent you from drawing cards, but only affects non-Creature spells and requires you to invest mana during your upkeep to keep around
As well as all of this, theres an alternate frame on some cards, called the Paranormal Frame
This means they have an ability that turns the cards over, a bit like transform, but they come together to make one double-sized card
In terms of MTG's color pie, black is the color that benefits from discard the most, and its usually the color that makes people discard the most too
While it's possible that increased scarcity is also a factor, it's also possible that the illustrations on these are more compelling than the one on 208s
Infinite Guideline Station I dont like Infinite Guideline Station, though I admit it has potential as a commander