Mono Black Aggro is a fast, grindy deck with Bloodghast recursion and small efficient creatures, so Arasta of the Endless Web's 3/5 reach body blocks well and punishes any of their rare instant-speed interaction. Setessan Petitioner gains a chunk of life off our green devotion (easily 3-5), which is valuable life-gain against their aggressive clock backed by Thoughtseize and Gray Merchant of Asphodel drains. Boseiju, Who Endures has few good targets here since they run almost no nonbasic lands or artifacts/enchantments, so it's a fine cut; Ulvenwald Oddity is too slow against their proactive aggro curve. Prioritize curving out dorks into bigger bodies since they lack much hard removal beyond Fatal Push and Bitter Triumph.