The most popular item was the Chocobo Bundle, which sold out very quickly
Id buy a set of Bloodbraid Elves ASAP just in case
Overwhelm your opponents before they can react, then sacrifice your hasty attackers to fuel your hand with fresh cards
Legions Landing / Adanto, the First Fort Double-Sided Playmat If protecting your cards while youre playing is what youre after, then youre going to want Ultra Pros Legions Landing playmat
If you remove an age counter from your own "Mystic Remora", you can keep the remora around for a long time, and if you remove a luck counter from an opponent's "Gemstone Caverns", you can even play a prank by preventing them from producing colored mana
Amass branches off into enough different strategies (aristocrats, tokens, +1/+1 counters, zombies matter) that its just an altogether good mechanic