This is the classic mirror where both decks fill their graveyard quickly, so Unholy Heat's delirium upgrade to 6 damage comes online fast and is excellent removal for Nethergoyf, Moonshadow, or Orcish Bowmasters. Molten Collapse is flexible removal that can hit a creature or planeswalker and often both modes if you've descended, making it great against Orcish Bowmasters or any threat. Street Wraith's swampwalk is irrelevant against another Swamp-heavy BR deck, and the extra Mishra's Bauble is less valuable when both sides are racing on resources. Thoughtseize remains premium since stripping their Flare of Malice or Thoughtseize protects your own game plan.