While Green is good at a lot of things, exile spot removal is tough
Ultima was a spell we knew we had to make
Chandra, Torch of Defiance is the Swiss Army Knife of red planeswalkers, and can fit well into almost any deck
Choco, Seeker of Paradise I imagine Choco, Seeker of Paradise will eke out Kastral, the Windcrested as EDHs best bird commander, if only because adding green to the mix makes any casual EDH deck better
With the Offspring keyword, you can have twin Agates doubling the damage
Currently the Active card draw in Amethyst can easily support an additional ink color without any of its own types of card draw (simply by adding Merlin - Rabbit and the bounce package), whereas in the First Chapter the passive card draw engine of Amber was needed to complement the small amount of Active in Steel or other colors (Amber-Steel was objectively the best deck in the Chapter One format)