And while he may only enable you to sacrifice one permanent per turn, team him with sacrifice engines like Viscera Seer, tokens or recurring permanents (like Bloodghast or the cat oven combo of Witchs Oven and Cauldron Familiar) to sacrifice, and drainers like Blood Artist and Mayhem Devil, and things snowball very fast
Best Dimir Token Commanders (The Scarab God, Oona, Queen of the Fae, and Wilhelt, the Rotcleaver) Oona, Queen of the Fae may not be a super popular commander nowadays, but in years past, it was common to see this powerful creature heading mill decks, Faerie decks, and Dimir good stuff builds due to her efficient ability to take cards away from combo decks and generate silly amounts of flying tokens from monocolor decks
So where would Black's weaknesses be
Each of these lands features a setting from the original series