Their Goryo's Vengeance deck has no real artifact or enchantment targets for Nature's Claim, so it comes out. Mystical Dispute is excellent here since their deck is loaded with blue spells (Quantum Riddler, Psychic Frog, Force of Negation, Spell Pierce), letting you counter their interaction cheaply, and the extra Pact of Negation protects your own combo turn from their Thoughtseize or Force of Negation. Endurance's enter trigger only puts a graveyard on the bottom of its owner's library in a random order, which is tempting against their Goryo's Vengeance reanimation plan, but with Mystical Dispute and Pact of Negation covering the spell itself it comes out too, and cutting one Griselbrand as well keeps the deck focused on winning fastest without overloading on big top-end.