That legendary artifact will prevent a damage from each source an opponent controls
A single Unsummon can occasionally steal the game by itself
Creature - Wurm Phyrexian Doors of Durin Whenever you attack, scry 2, then you may reveal the top card of your library
That is, assuming you don't run cards for their flavor or because you just like them
By sacrificing an artifact creature, which is simple in token-heavy builds, you get to search your deck for any noncreature artifact and put it right onto the battlefield
Although, we are sure that some stores, at least locally, allow you to buy all 4 decks for a slightly cheaper price, therefore making all the decks cost pretty much the same