Goryo's Vengeance wants to discard Griselbrand or Atraxa and reanimate them with Goryo's Vengeance or Faithful Mending-fueled loops, and Rakdos Charm provides effective graveyard hate since its instant-speed mode can exile their graveyard in response to Goryo's Vengeance to remove the target and stop the reanimation spell from resolving. The extra copies of Rakdos Charm are also useful proactively to strip their graveyard before they can Goryo's Vengeance back Atraxa or Griselbrand, buying a turn of disruption. Village Rites is cut since it's a low-impact card-draw spell that doesn't pressure their combo plan or protect against their many free-ish counterspells (Force of Negation). This is a difficult matchup to sideboard for given the available cards, so the plan is intentionally light.