Containing 12 cards, Disney Lorcana booster packs mirror the pattern of just about any trading card game you can think of, in that they contain 6 common cards, 3 uncommons and then 2 cards at the rare of higher level, as well as a foil treated card of any rarity
It usually appears on creatures and adds power and toughness to the board, either temporarily or permanently, with a few undergrowth cards having slightly different effects
Black needs green to do what it cant do itself
Proliferation effects are also important, as are counter-doubling effects like Vorinclex, Monstrous Raider and Doubling Season
These are often strong in the sideboard of formats like Modern or Standard where you can bring them in when you know what youre facing
FAIR USE DISCLAIMER As usual with these sorts of lists, Im more interested in capturing an interesting cross-section of powerful spells than I am in choosing a strict definition of what makes one best