We can't explore those details here, but we can introduce all the new mechanics appearing in Duskmourn: House of Horror so you can avoid at least one of those greatest fears: going to the Prerelease unprepared
Graded Population Report: Alolan Graveler #36 Visualize the distrbution of grades in the chart
The Emerald Sapphire deck is all about Inventors with a tonne of new mechanics that buff every Character with that Keyword
From another direction, Mind Rot reduces the cards in your opponents hand to give you card advantage, yet has nothing to do with card draw
Or Niv-Mizzet, the Firemind
This enchantment improves with cards that let you see or manipulate the top of your library, like Sensei's Divining Top, and you can even activate the Top, triggering revolt and placing a permanent on top of your library