Belcher is a fast combo deck relying on Goblin Charbelcher and heavily blue support like Whir of Invention and Sea Gate Restoration; Consign to Memory counters their many colorless spells such as Lotus Bloom and Goblin Charbelcher itself, while Mystical Dispute is cheap and efficient against their blue-heavy suite of Counterspell, Disrupting Shoal, and Sink into Stupor. Thought Scour and Persist are cut since they're too slow to matter against a deck that can kill on turn 1-3; you need maximum disruption and speed instead. Prioritize Thoughtseize to strip their combo pieces and Spell Pierce to counter their noncreature spells, and race with Psychic Frog and reanimated threats before they assemble Charbelcher.