To sing a 10-cost Sing Together song you could: exert ten 1-cost characters, or one 10-cost character, or one 2-cost, one 3-cost, and one 5-cost
But right now, one such set is up for sale, and its honestly not as expensive as you might expect (yet)
Like every other set, there will also be returning creatures like the Sliver Overlord in new poster artwork, as well as a variety of new artwork and special card treatments exclusive to Edge of Eternities
Abazan is probably the Tarkir Wedge for you
You either play a black midrange style deck to wait for those so you can get Tetzimoc in hand to do the reveal trick to do a board wipe, you know more midrangey things, or you toss in a bunch of tutors to make a more expensive way to do midrange from the command zone