Depending on the format, you can use your trusty turn-1 Llanowar Elves to set up your future plays, or you can use cards like Elvish Archdruid and Priest of Titania to produce tons of green mana depending on the number of elves you have on the battlefield
Court of Ardenvale AND Court of Grace Hello and welcome to our pair of four-cost enchantments make you the Monarch on arrival to the battlefield and then in your upkeep you'll get a trigger that's better if you have the Monarchy and kept it for a round of turns
Were your expectations met
Great fog and a great rate
Although it will be rarely correct to do so, you can curse yourself with Clinging Webs if you're anticipating a board wipe to turn all of your creatures into mini Penumbra Spiders
Black-green is one of my favorite color combos to begin with, and Eldraine is full of fun cards like Bake into a Pie, a black instant that destroys a target creature and bakes them into a Food token, Sweeney Todd-style