Black Cards Apart from Cryptbreaker, which is mostly just for Zombies, we got three other mono-black cards in our initial dump of Historic cards, in Hypnotic Specter, Phyrexian Arena, and Tendrils of Corruption
You can get codes from 3rd party stores that collect codes from players who don't need them and resell them to you
Its also possible to link many changelings under Morophons wings and add different typal benefits as well, like Seshiro the Anointed
You'll be making the most of the Goad mechanic, which makes players attack each turn if able, and, if possible, any player other than you
So look for ways to get a little more value out of your artifacts
We get to apply our normal power-level heuristics and leverage our Future Future League for Constructed testing