Missing sideboard cards? The full 15-card sideboard runs about $119.
Buy sideboard on ManapoolThis is a grindy mirror-style tempo matchup where cheap, efficient removal for Nethergoyf, Moonshadow, and Orcish Bowmasters matters most; the extra Solitude gives you another strong answer to their best threats, and it can be evoked for free if you need to tempo them out. Erode is clean one-mana removal for their creatures or planeswalkers like Kaito, Bane of Nightmares, but note that its controller may search for a basic land, so the opponent gets the land, not you. That fetched land makes your Wasteland less effective against them, so save Erode for high-impact targets. Witch Enchanter's artifact/enchantment destruction is mostly dead since they run very few noncreature permanents worth hitting. Keep your Thoughtseize and Swords to Plowshares suite intact since discard and removal are premium against their disruptive plan.
Deafening Silence caps each player at one noncreature spell per turn, which pinches their Swords to Plowshares, Static Prison, and Goblin Bombardment while you lean mostly on creatures. It does not shut off Ocelot Pride, whose end step trigger only cares whether they gained life that turn (from lifelink, Guide of Souls, and the like). It also limits your own Thoughtseize, Cabal Therapy, and Swords, so sequence carefully. Wrath of the Skies is a scalable sweeper that can wipe their wide board of Cat tokens (mana value 0) and smaller creatures like Guide of Souls, but it destroys your own artifacts, creatures, and enchantments at or below the same mana value, so fire it off when you are behind on board rather than ahead. White Orchid Phantom's land destruction is low-impact against their already-aggressive curve, and Overlord of the Balemurk is too slow and clunky against a deck that races and punishes durdling. Keep Orcish Bowmasters and Thoughtseize in, since they're excellent proactive and reactive pieces against this matchup.
Containment Priest is strong against the Show and Tell plan: any nontoken creature that enters without being cast, such as an Atraxa or Acererak put onto the battlefield by Show and Tell, is exiled instead. It does not stop Aluren, because creatures cast for free through Aluren are still cast, so plan to answer Aluren another way. Witch Enchanter is a good answer to that problem, since it destroys Aluren or Omniscience (or a Lotus Petal) when it enters, so keep both copies in. Faerie Macabre is a flexible 2/2 flier that can also be discarded to exile up to two cards from graveyards, though their main deck leans on its graveyard very little, so treat it mostly as a cheap evasive body. Damping Sphere blunts their fast mana, because Ancient Tomb and City of Traitors will each produce only a single colorless mana, and it taxes every extra spell they cast in a turn, which makes Aluren chains more expensive. Flickerwisp is a weak proactive play here, and any creature it flickers would be exiled by our own Containment Priest when it returns. Ajani is a slow blocker when discard and tempo matter more. Overlord of the Balemurk is also slow in this matchup, since its cheap impending mode does not give us a creature for several turns, so two copies make room for the better cards.