mtg pro player cards Liliana of the Veil · Tour Promos (PPRO) #2015 · Scryfall Magic: The Gathering Search Balance — Pro Tour Collector

This gives us 14 sources for each colour (since [Card]Ash Barrens[/Card] replaces itself its more utility) and 16 slots to play with for basics and utility lands

36x Forests

My guess is that a lot of Unstable will be sold to players who simply want to experience the novelty of the format once, so they pick up a box to draft with their play group or at their local game store

As a 2/2 for 2, Stubborn Burrowfiends already a fair rate in a Limited environment, and its triggered saddle effect gets progressively stronger each time you activate it milling more and more creatures into your graveyard results in a bigger buff for the Burrowfiend