mtg grixis cards Demon : r/custommagic Secret Lair 3 Color BUR (Grixis) (Visual)

Most likely both

About which packs to buy, actually it does not matter that much since the probability of getting what you want is low, but, to maximize it, Id recommend getting Amonkhet for Hazoret the Fervent, Glorybringer, Ahn-Crop Crasher, Magma Spray and Sunscorched Desert

Its a cheap and useful counterspell, and given the sheer amount of Legendary Creatures in most decks these days, its not the biggest deal to sometimes pay this additional cost

Guided by Nature The green preconstructed deck was forgettable, but the two legendary permanents that came out of this deck are some of the most popular mono-green utility cards that have seen print: Freyalise and Titania

Vivid Crag The Vivid lands are all functionally the same until they run out of counters

In cube this is painfully slow and frequently a liability