Orzhov Midrange's biggest swings are The Wandering Emperor and Elspeth, Storm Slayer (both mana value 4-5), which Disdainful Stroke counters before they generate card or board advantage. Abrade is a clean answer to The Ooze or any small creature like The Queen of Dale. Lightning Axe is a worse fit against a deck already attacking your hand with Thoughtseize, since paying the discard cost compounds their disruption plan, and their creatures are generally efficient 2-for-1s (Skyclave Apparition, Graveyard Trespasser) that punish you for falling behind on cards. Keep Fiery Impulse and the remaining Lightning Axe copies to handle Skyclave Apparition and Sanctum Lurker before Unholy Annex // Ritual Chamber's Demon token or their planeswalkers take over the game.