The last at #6 below is from a block often nicknamed as "The Artifact Block" by players, although it actually had an enchantment theme
Two-damage pinging is nice, but frankly this design should have been saved for a snapping turtle or something
If your Extremely Slow Zombie faces an opponent's creature with no strike abilities, the opponent's creature will deal combat damage first (when most creatures deal combat damage)
That said, unless you are planning on opening a lot of boxes (to help even out variance), I'd probably plan on getting the non- Masterpiece value and treat the possibility of opening a super-sweet, super-expensive Invocation as a bonus lottery ticket that you get for free when buying a box of Amonkhet
The Brothers War picks up right where DMU left off, with Teferi somehow opening up a portal to the past in order to try and figure out how to work Karns Sylex, rebuilt by Saheeli