Use Accel Synchron and Mecha Phantom Beast Token to Synchro Summon Dark Flattop
That means it might not net you that much mana and you might not have much to spend it on when it does, and, as mentioned, two mana is an enormous amount to hold up
(Once harnessed, its Infinity ability is active.) - At the beginning of your upkeep, return target creature card from your graveyard to the battlefield
Not only is it helpful to know what removal spells are available when drafting a particular color, but it helps you know what to play around when facing off against opposing decks
Its effect is a perfect counter that doesn't even have turn 1, let alone turn 1, and you can choose yourself to return Mist Valley to your hand, so it's a very good performance that can interfere with 1 even by itself
You're much more likely to open multiple rares in Set Boosters than in Draft Boosters