Lifegain's entire plan revolves around lifegain triggers feeding Amalia Benavides Aguirre's explore counters and Case of the Uneaten Feast's graveyard recursion, and Rest in Peace exiling all graveyards cuts off the Case's solved ability that lets them recast creatures. Burst Lightning stays in the deck here: its 2 damage easily kills Enlightened Confidant, Hinterland Sanctifier and their other small creatures, and only Haliya, Guided by Light survives it unkicked. The slow five-drops are the better cuts, since this matchup rewards a low curve and cheap interaction over top-end. Race aggressively and target Amalia early (remember her ward costs 3 life) before she can explore her way to a board wipe threshold.