If theres a card you need that gets milled, just think of it the same as being on the bottom of your library
We knew it was the kind of mechanic that would have a lot of weird corner cases, but after much playtesting, we felt it was something that added a lot to the set and chose to keep it in
You get a set of exclusive cards that form a panoramic scene, matching art-only versions for display, and 3 boosters to open
Stoneforge Mystic does that with equipment, preferably those that have mechanics like living weapon or for Mirrodin!, which are put into your hand and later onto the battlefield
In a game where just one turn can make all the difference in a match, its no surprise that Time Walk was given a place among the Power Nine and ultimately added to the Reserved List
Phyrexian Metamorph This is an awesome, super flexible card