That does some wild stufffor example, it gets Marsh Flats back twice for actual land ramp in Orzhov, it lets you feed cards like Dusk Legion Zealot into a Warren Soultrader multiple times, or it wrings the most value possible from cards like Boromir, Warden of the Tower and Dauthi Voidwalker
This is a deep set, and in my initial look over the spoiler I pulled out 59 cards that are worth mentioning, although 5 of those are a cycle, that are strong additions to casual play and formats like Commander, Five Color, multiplayer, and loads more
But for now, if you haven't played with Prototype yet, now's the perfect time to get to tinkering
That being said, there are some things which are so universally unsettling that theyll put The Fear into basically anyone who thinks about it or looks upon it for long enough