While Sram, Senior Edificer is also good draw, its only off of cast, and so should always be second choice to Puresteel
Secondly, in decks with a way to sacrifice a lot of cards for value before bringing them back for another go around
Great in all format, and even better in Commander, where your opponent gaining 7 life isn't that big of a deal
Good Budget Ruby/Emerald Deck This starter deck's greatest strengths are its Evasive characters and its ability to remove threats from the board, so this build emphasizes both of those strategies, while also aiming to make the deck more consistent
I am 99% sure that Phyrexia is going to invade Kaladesh, with it either happening in the next set, or very clearly setting up the invasion for our return to Kaladesh the next time around