Belcher is a fast combo deck aiming to assemble Goblin Charbelcher off cheap artifact mana like Lotus Bloom, so proactive discard and disrupting their mana are crucial since they run few creatures for our removal to hit. Extra Inquisition of Kozilek strips Lotus Bloom or a key protection spell like Disrupting Shoal or Force of Negation before it matters. Surgical Extraction can exile all remaining copies of Goblin Charbelcher or Lotus Bloom once one hits the graveyard, and Damping Sphere taxes chained spells during multi-spell combo turns by making each spell cost more for every other spell cast that turn. March of Wretched Sorrow and Force of Despair are nearly dead since Belcher runs almost no creatures, so they're cut entirely for more relevant disruption.