Cards such as Paper Tiger, Rock Lobster, and Scissors Lizard may technically all be playable in Eternal formats
From what I can tell it has MOST of the cards on forge, although several may have slipped through the cracks, because of various downloading errors
2 is hopefully the last gasp for this particular product
In my experience, the Game Changers that win the most games are the ones that generate persistent card advantage: Rhystic Study, Smothering Tithe, Necropotence
Cards like Savage Ventmaw (plus a mana dork), Grand Warlord Radha, or a ton of mana dorks convert this into easy infinite extra combats
At least for a casual power level, the important questions I think we should ask are which themes play well together, which themes are well supported and which themes fit best into a viable Commander gameplan. For the first answer, it feels like there are two sets of synergistic themes that happen to align neatly with the two blocks of rules text