The problem in cube is mostly that of space, finding something you can do without in your list so as to put in the Abeyance
Brawl Not Legal Vintage Legal Timeless Not Legal Commander Legal Pauper Not Legal Oathbreaker Legal Penny Not Legal Toolbox Buy This Card Notes and Rules Information for Chaos Moon: In Two-Headed Giant, triggers only once per upkeep, not once for each player
In terms of card quality, you'll bump into the following: Near Mint Lightly Played Moderately Played Heavily Played Damaged Buying a "Near Mint" quality card from TCGplayer does not mean that it will grade a PSA or CGC 10
Even more so if it turns your deck from $50 to $200 for only a minute percentage of increasing your win rate
Just turn around, go back downstairs, and never think of doing this agai It becomes pretty awkward when Nissa suddenly opens the door
If you manage to do all four in a single turn, you can also transform Avatar Aang into Aang, Master of Elements a flying creature that reduces spell costs significantly, and lets you transform back for life gain, card draw, counters, and damage