Consign to Memory costs only {U} and can counter a colorless spell or a triggered ability, so it picks off Mishra's Bauble or a trigger like Dragon's Rage Channeler's surveil, Murktide Regent's counter trigger, or a Cori-Steel Cutter flurry trigger. That is cheap interaction against a deck that can Daze and Force of Will your spells while you're trying to assemble a combo. Their threats are not colorless, so it will not counter the creatures themselves. Magus of the Moon turns their nonbasic lands, including Wasteland and their Volcanic Islands, into Mountains. That cuts off their blue mana and hampers Murktide Regent, and it also serves as a body that pressures them to find removal like Lightning Bolt. Spell Pierce and Prismari Charm are the easiest cuts since you'd rather have cheap interaction for triggers and a mana-disrupting threat than situational plays against their efficient, low-curve aggro-control shell.