It's totally achievable in a Golgari commander deck, particularly if you run a lot of mutants as well
They are significantly more expensive and do not provide a playable deck or a structured starting point
The trouble is, of course, that you can only run Contract From Below if you're playing for ante, i.e
If the target becomes illegal before the ability resolves, the ability does nothing
For example, Monastery Swiftspear would get two instances of prowess if Bria, Riptide Rogue is on the board, so casting Brainstorm would give Monastery Swiftspear +2/+2 until end of turn
Throughout much of Murders at Karlov Manors spoiler season, Wizards has been surprisingly tight-lipped about this new product