black card advantage mtg The Basics of What is your best generic

Errors are red, and the archenemy of red in the color pie is blue

The low mana cost makes it an effective target for a Whir of Invention to catch opponents by surprise and stop them from making explosive graveyard plays

You could stack Starlight Vials and really reduce your action costs, but most actions you want to play top out at around 5 ink anyway, so you're going to hit diminishing returns

Just the fact that you can proliferate at will gives Yawgmoth many routes for deckbuilding, and it can sometimes be seen in other formats like Modern

How did this deck work

This is especially true once you move beyond mono-color decks and start exploring other strategies and formats where multicolored mana bases get more ambitious