These are the generally safe cards to buy in black because they will always be good to play in most B/X or X/B commander decks. (I'm leaving tutors out of this list because I feel they are obvious. Cards that let you get your best answer at any given point are always good.) (Also, for certain cards in here, make sure casting them is reasonable for your deck. If you can't hit BBBB by 5, maybe don't run the obliterator.) :)
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