This is a go-wide token mirror-ish battle, so Wrath of the Skies as a scalable sweeper is the single best sideboard card against Ocelot Pride tokens, Cat Warriors, and small value creatures. Thalia, Guardian of Thraben and Thoughtseize stay in since they're both racing and disrupting similarly, and Skyclave Apparition remains great against their small threats. Keep Solitude and Swords to Plowshares in for their efficient one-for-one removal against key Cat Warriors or Ajani.

Faerie Macabre and Surgical Extraction are the graveyard hate for this matchup. Nethergoyf's power depends on the card types in their graveyard, and its escape needs four or more card types among the other cards there. Bilbo can also recast artifacts, instants and sorceries from their graveyard. Containment Priest stays in the sideboard. Escaped Nethergoyf is cast from the graveyard, so Priest does nothing against it, and Priest would exile our own creatures that enter without being cast, such as those put in with Aether Vial. Witch Enchanter has few targets here beyond Mishra's Bauble, and Pre-War Formalwear is the clunkier card, so those two make room. Keep Thoughtseize and Solitude in as premium interaction against their disruption-heavy plan. Wasteland and Karakas remain crucial since their manabase is nonbasic-heavy and Karakas bounces legendary creatures like Bilbo, Thief in the Night.

Containment Priest is a useful sideboard card versus Sultai Aluren, but only against Show and Tell: it exiles Atraxa, Grand Unifier or Acererak the Archlich if they are put onto the battlefield that way, since those creatures weren't cast. It does nothing against Aluren itself, because creatures cast for free with Aluren are still cast. Faerie Macabre (only one copy available) is mainly a flying body, with its discard ability as extra flexibility. Thoughtseize remains premium, stripping their Show and Tell, Aluren, or Acererak before they combo off. Keep Wasteland in to punish their Ancient Tomb/City of Traitors-dependent fast mana.