As mentioned before, Blue decks promote card-drawing while Black decks promote lifesteal and "death and taxes" playstyles
The problem, at least with my initial experiment, is that leaning too heavily on a mechanic at the expense of what can only be described as "essential ingredients" of a good commander deck will result in a deck that is just a bit too janky
For example, you could have a deck with Jarad's Orders and/or Buried Alive, and you could stock up to either pull stuff out of your 'yard with the Soul or to put the Soul there to yank out its friends
After much debate, it was actually the pitch cards that pushed us to do it
Theres a shortage of good universal interactive creatures in Pioneer the way Modern has Thalia, Guardian of Thraben and Meddling Mage, but there isnt a shortage of specific hate bears to load up the sideboard
Give [Rush] to cards with powerful [When Attacking] K.O