Golgari's removal suite (Fatal Push, Abrupt Decay, Go for the Throat) and Sheoldred punish going over the top with one big Craterhoof turn, so trim to two copies and bring in Nylea's Disciple for life gain to blunt Sheoldred's drain and Professor Dellian Fel's drain combo. Reclamation Sage answers Unholy Annex // Ritual Chamber and any artifacts/enchantments they bring in post-board. Note Boseiju, Who Endures is already in our 40 as a land that can Channel to blow up their own problematic permanents, so don't cut it for a land-neutral swap — keep the manabase intact and treat this as a pure spell-for-spell trim.

Reclamation Sage comes in as a cheap body whose enter trigger can destroy Enduring Innocence, which is an enchantment creature and stays an enchantment after it returns from dying. It cannot target Elspeth, Storm Slayer (a planeswalker) or Archon of Emeria (a creature), so those need to be handled by pressure and blockers instead. Skyreaping deals damage equal to your devotion to green to each creature with flying, which makes it mainly an answer to Archon of Emeria (a 2/3 flyer) once your devotion reaches 3, or to any creature Elspeth has given flying. It does not hit the Illusion tokens from Skyclave Apparition, since they have no flying. Your own creatures don't fly, so it carries little risk to your board. Elder Gargaroth provides a sticky, efficient blocker with reach and vigilance that stonewalls their Collected Company creatures and generates incremental value against their grindy plan. Craterhoof Behemoth and Titan of Industry get cut since Archon of Emeria's one-spell-per-turn restriction and their efficient removal suite make it harder to assemble a big alpha strike. Boseiju comes out since its channel ability mostly trades for a nonbasic land or Enduring Innocence while letting them fetch a land with a basic land type, which is less impactful than the bodies you're adding.

Izzet Cauldron is a Vivi Ornitier and Agatha's Soul Cauldron spells deck. It grinds with card draw and selection (Winternight Stories, Proft's Eidetic Memory, Stormchaser's Talent) and tempo bounce (Boomerang Basics, This Town Ain't Big Enough) rather than hard removal, so resilient bodies that dodge their small burn are key. Vivi Ornitier and Agatha's Soul Cauldron are the permanents that matter most, so keep Tail Swipe and Boseiju for them. Elder Gargaroth is excellent here: its 6/6 body shrugs off Torch the Tower, and it has reach to block Quantum Riddler. The repeated value (tokens, life, cards) outgrinds their card advantage plan. Keen-Eyed Curator is a reasonably efficient clock, and its {1} ability can exile Winternight Stories from the graveyard to stop its harmonize, or exile other cards before Agatha's Soul Cauldron can use them. Titan of Industry stays in, since its artifact/enchantment mode has real targets in Agatha's Soul Cauldron, Stormchaser's Talent, Proft's Eidetic Memory and Fear of Missing Out. Badgermole Cub is lower impact against a deck without much pressure to race, and Craterhoof Behemoth is too slow and clunky against a deck that can bounce its expensive threats.