If youre looking to increase power level, you can add a few tutors to help find your key pieces
Although you'd be in mono-Black, likely with Cabal Coffers and other mana ramps, so that may not really be something you care about
I bring this player up because his love of milling would lead to the creation of a huge amount of milling cards, including a few sets with strong milling subthemes
Artifacts and enchantments are plentiful, specifically equipment and sagas, and you can fit more of them in your deck due to them being creatures (or making creature tokens on ETB)
Its only new card is Self-Destruct, which gives an amusing way to get extra value from a Screaming Nemesis or Heartfire Hero
A range of conditions, from Near Mint (NM) to Good every card has its own story