Mono Black Aggro floods the board with cheap threats like Bloodghast and Stitcher's Supplier, and Extinction Event choosing even exiles Bloodghast, Gifted Aetherborn, and Liliana the Repentant without letting Bloodghast return via landfall, since exile bypasses the graveyard. Choosing odd instead exiles Stitcher's Supplier, Dark Matter Manipulator, Baron Helmut Zemo, Gray Merchant of Asphodel, and Overlord of the Balemurk once it becomes a creature, so pick whichever half of their board is doing more. Note their sideboard brings in Leyline of the Void, which exiles cards that would go to your graveyard, but your Graveyard Trespasser and Restless Cottage can still exile cards from their graveyard. Culling Ritual only hits mana value 2 or less, so it misses Baron Helmut Zemo, Ral Zarek, Gray Merchant of Asphodel, and Overlord of the Balemurk, and it also destroys your own Badgermole Cubs and any Bloodghast it kills can come back with landfall, so the cleaner Extinction Event is better. Keep Fatal Push for cheap creatures like Gifted Aetherborn and Dark Matter Manipulator, and keep Bitter Triumph for bigger targets like Gray Merchant of Asphodel, which Fatal Push cannot reach.