Orzhov Midrange leans on planeswalkers like The Wandering Emperor and Elspeth, Storm Slayer alongside enchantments like Caretaker's Talent, none of which Culling Ritual answers well since their permanents mostly cost more than 2. Invoke Despair is excellent here, forcing a creature sacrifice, then an enchantment sacrifice, then a planeswalker sacrifice in sequence, which can single-handedly unravel their board. Your removal suite of Fatal Push, Bitter Triumph, and Abrupt Decay already lines up well against Skyclave Apparition, The Ooze, and The Queen of Dale, so no further changes are needed there.