With such weird cards being printed, Wizards of the Coast has had to find ways to make sure people don't accidentally put a card with Denimwalk (can't be blocked by a player wearing denim) or Art Menace (can only be blocked by creatures with two or more characters in their art) into their normal Magic decks
You only get this trigger once each turn, but getting to see three cards deeper into your deck every time you sneak in a creature is a great boost to your deck
Pair these with card draw punishes like Sheoldred, the Apocalypse or Scrawling Crawler, and you can whittle your opponents life down without even attacking
The second is Faithless Looting, and Im not going to talk in depth about the specifics of this piece because there has been more than enough discourse over the last few weeks
Quick hits on forums doesn't really do the same thing for me, at least not before I have a baseline
As an aside, when one is speaking about flipping for a creature off the top of the library, that's specifically a "Polymorph" effect, and for a non-creature, it's a "Scramble." Creature The classic enablers for Polymorph strategies are unique in that they contain an artifact, meaning Blue as a color can tap into their tutor-ability both as Sorceries, and artifacts
