This is certainly one of the more obscure things to be protected from, but it fits into the game perfectly from a gameplay and theme standpoint
However, it does suit well to blacks style of gaining life in big chunks to pay out for resources, which is what well be doing in big swings with Beledros Witherbloom
Magic: The Gathering Arcane Wizardry Sealed Tribal Deck (Wizards of the Coast, 2017)
Mana costs can include specific colors of Mana, or generic Mana, which can be Mana of any color
You don't need to attack with Cait Sith, Fortune Teller to gain the impulse card and free scry, but depending on the mana value of that top card, you may want to attack
If you were to compare the prices of Lorcana cards to the prices of other games (Pokemon, Yu-Gi-Oh, Magic the Gathering etc.) you will find that they aren't worth as much