Your "x" cards have a wide variety of effects, so you should have a good selection to choose from depending on the game state
Once Bolas flips, games usually spiral fast
Its important to note that youre activating an ability, not casting a spell, so you cant counter a forecast effect with just any counterspell
Vivi Ornitier Vivi Ornitier is to Final Fantasy what Orcish Bowmasters was to Lord of the Rings : the most obviously overpowered creature in a Universes Beyond set, so strong that it feels like no internal testing really happened with the card
Sac lands, cycling lands and an abundance of other effects, many of which are black and green, easily fill the yard full of lands to allow prolonged mana influx from the Shaman
But the main reason for building so many decks is a simple one