Obsidian Acolyte has protection from black, making it immune to Cast Down, Defile, Snuff Out, and Unmake, letting it block or attack profitably against a mono-black removal-heavy deck. Standard Bearer forces their targeted removal like Cast Down or Snuff Out onto itself, protecting our more important threats and creating good trades against their disruption suite. Bitter Reunion and Sandstorm Eidolon are cut since they don't address the opponent's steady stream of removal and sacrifice-value creatures like Refurbished Familiar-style effects (via Eviscerator's Insight and Fanatical Offering). This is a grindy matchup where surviving their removal and attrition engine matters more than raw card filtering, so prioritize resilient bodies.