Daggerfang Duo I get that self-milling when Daggerfang Duo enters can be useful in some decks
In a set booster, you are guaranteed to open one, just like you are in a draft booster, but thanks to the wildcard slot and the "foil in every pack" slot, you have a chance at opening up to three rares or mythics in a single pack (and technically four, thanks to the new-to-Modern reprint slot)
March of the Machine Aftermath Epilogue Booster Box
You'll explode out the gate in a shower of fast mana, looking to combo off on turn one or two or die trying
Considering you've just cast your Zacama, you can bet you'll have nine mana worth of lands in play, which means you could activate any of the three, up to three times, colored mana permitting