Thanks to the color-shifted cards in the Time Spiral block, Green also has access to [card]Harmonize[/card], providing three cards for just four mana
For example, you could save two 2/2 creatures, or a 1/1 and a 3/3 creature, but not all four of those creatures
Sources: TCG Player/Mewtwo VSTAR, TCG Player/Mewtwo V Alt-Art, TCG Player/Radiant Charizard, TCG Player/Radiant Venusaur, TCG Player/Radiant Blastoise, TCG Player/Radiant Eevee, TCG Player/Dragonite VSTAR, TCG Player/Spark Trainer, TCG Player/Candela Trainer, TCG Player/Blanche Trainer
The Matchmaker is useful as well, removing a lore from an opponent whenever she challenges another character, and then Stitch (Alien Troublmaker) allows you to draw a card and gain 1 lore whenever he banishes another character in a challenge
Its also necessary thanks to the number of turn 1 combos that rule those formats
The magic here is in the modality