The Amber and Amethyst deck is probably the easiest to master, while the Ruby and Emerald deck is the trickiest of the three to understand, although its probably the most flexible and adaptable of the three decks
Black Cards are focused on sacrificing your own creatures and spells and then allowing you to search your deck for specific cards needed for combos
Wed say the best opener would be Rudy Groove Disruptor as Little John Camp Cook doesnt fit into the deck well unless you can use Food Fight
Not only is Yuna excellent for ramping up your board state with more powerful creatures, but Yuna ensures that any buffed creatures don't go to waste, repeatedly recycling counters to summon an overwhelming stream of powerful beasts
It doesn't have to be your own character, either
Evocative, powerful, and relatively affordable, Living Death is a true black staple