Mono Black Aggro floods the board with cheap, resilient threats like Bloodghast, Overlord of the Balemurk, and Baron Helmut Zemo, so bounce is too slow since many of these come right back or are cheap to replay. Redcap Melee is efficient one-mana removal that kills Baron Helmut Zemo and Gifted Aetherborn, but nearly every target they have is nonred, so you will sacrifice a land almost every time you cast it. Treat it as a tempo play for key threats and don't fire it off carelessly. Abrade deals 3 damage to Dark Matter Manipulator and can kill an animated Hive of the Eye Tyrant. This is a race, so prioritize cheap interaction over card selection luxuries like Galvanic Iteration.