Alchemy is one example, as you wont be able to play it on Magic Online or in paper
My favorite Black Magic games on either side involve incremental sacrifices for ultimate gain, rather than a big broken play that wins or loses, depending on if Griselbrand gets it done on his own or not
At the beginning of that turn's upkeep, cumulative upkeep adds an age counter and then says, "Hey, pay 1." (This assumes your abilities can speakmine can.) Echo sits mostly quietly, though it occasionally mumbles about the old days
But this card isn't a great choice if you want a commander that's more than just a one-time bomb
Now lets go deck by deck and showcase what each one has to offer
The Crownless (GW) Mechanic: Supply COST (At the beginning of your upkeep, you may supply one of your unsupplied creatures