We have only mythic rares, rares, and uncommons
For example, playing Mother Gothel - Withered and Wicked and Rapuznel - Gifted with Healing in the same turn is not only extremely flavorful, but ends that sequence with a 3/4/1 and a 1/5/2 in play with three new cards in hand for six ink
Blue-Red Big Noncreatures Cast massive spells for massive value with a blue-red deck
I prefer Cabal Initiate a lot, especially because Viashino Lashclaw become a Grizzly Bears in the late game
Diamond Weapon Commanders with innate mana reduction are always handy because cost reduction reduces command tax, so its easy to cast Diamond Weapon multiple times in a game
Enduring Enchantments has some stellar Constellation/Constellation adjacent cards, with Composer of Spring likely to be the one to watch