Lifegain decks like this one rely heavily on small, cheap permanents (Hinterland Sanctifier, Liliana the Faultless, Case of the Uneaten Feast) to trigger their life-gain payoffs, and Pest Control sweeps all of their mana-value-1-or-less permanents at once, including those three and any Pest, Bat, or Cat tokens, hitting multiple engine pieces. Note that it does not touch their two-drops like Enlightened Confidant, Starscape Cleric, or Amalia Benavides Aguirre. Strategic Betrayal makes them exile a creature of their choice along with their graveyard, so we can't pick Amalia or another key creature, but it still strips the graveyard and shuts down recursive value from Moseo, Vein's New Dean. Lightning Helix is a fine one-for-one but scales poorly against an engine that floods the board with small bodies, and one Consult the Star Charts comes out in favor of more proactive answers since this is a grindy matchup where we need to interact with their engine rather than just draw cards.