This matchup is a pure speed race against a reanimator deck that can win as early as turn 1 with Griselbrand or Atraxa, so Thoughtseize helps strip a key piece like Reanimate or Animate Dead on the draw. Hexing Squelcher doesn't stop their reanimation targets directly but its Ward and uncounterable clause help our own combo resolve if we need to race through their disruption like Unmask or Cabal Therapy. Giant's Boulder and Song of Creation are far too slow against a deck that can deploy a 7/7+ threat before turn 2. We must prioritize going off as fast as possible since there is little true interaction we can bring in against their graveyard-based plan.