Veil of Summer is strong insurance against their Thoughtseize-heavy sideboard plan and gives us hexproof from blue/black disruption. Prismatic Ending can exile key mana creatures like Elvish Mystic, Llanowar Elves, or Quirion Ranger, or even strip away problematic permanents like Allosaurus Shepherd before it shields their green spells from our Force of Will. Omniscience and the extra Atraxa are too slow against Elves' explosive Natural Order and Craterhoof Behemoth lines, which can end the game well before those cards matter. We retain our full combo suite and mana base since this matchup is primarily about who assembles their engine first.