Rakdos Delirium is a graveyard-fueled aggro-midrange deck with efficient removal like Lightning Bolt and Flare of Malice and discard like Thoughtseize, so Six gives you a resilient 2/4 Reach blocker that also mills itself to find lands, functioning well against their removal-heavy plan. Collector Ouphe doesn't hit much here since they have few activated abilities, so treat it as a replaceable body rather than a key disruption piece; only bring it if you need another blocker. Cutting Summoner's Pact removes a card that's risky against discard (Thoughtseize can strip your payment plan) and a deck that can punish the delayed mana commitment. This matchup is close to a straight race, so prioritize surviving their removal suite over maximizing combo speed.