This is the mirror, so the game is won on card advantage and disruption rather than raw removal since both sides run the same core engine pieces. Duress strips their Strategic Betrayal, Requiting Hex, or other key noncreature spells from their hand before they can cast them, which is huge in a mirror where sequencing matters. Strategic Betrayal makes them exile a creature of their choice (so expect them to give up their least valuable one) and also exiles their graveyard, shutting off their Lively Dirge reanimation. The Ooze provides incremental value and can exile cards from their graveyard to blunt Lively Dirge. Deadly Precision costs extra resources that are too valuable in a grindy mirror, and Obsessive Pursuit is slow against an opponent racing on the same axis.