Nature's Claim has some targets here (Detective's Phoenix, Fear of Missing Out, Mishra's Bauble, Nihil Spellbomb), but those are cheap, low-impact permanents and Claim gives them 4 life, so the two Claims are better replaced by proactive cards. Veil of Summer stays in: Rakdos Delirium casts plenty of black spells, so hexproof from black stops Thoughtseize and Orcish Bowmasters from targeting us, and it draws a card when they cast a black spell. Be aware it does nothing against Lightning Bolt, which is red, or Flare of Malice, which doesn't target. Xenagos and Hooting Mandrills are the slower, clunkier cards in this matchup, so they make room for the new additions. Fanatic of Rhonas is a good fit against their Thoughtseize-heavy disruption: it is a mana creature whose 4 toughness survives Lightning Bolt, it helps us rebuild mana after a discard spell strips a combo piece, and it can ramp toward Ferocious once a big creature is out. A fourth Pact of Negation gives more free protection against Thoughtseize and Flare of Malice disrupting our combo turn, as long as we can pay for it on the next upkeep. Play around Thoughtseize by holding back key combo pieces and using Fanatic of Rhonas to rebuild mana after disruption.