Omniscience Combo needs to cast Omniscience with Uthros and Roiling Dragonstorm to end the game immediately. Duress at 100% SB prevalence is your best card, stripping Omniscience and their tutors from hand before they can set up. Annul counters key enchantments in their combo including Omniscience and Grand Abolisher. Disdainful Stroke hits their expensive combo pieces on the stack. Cruelclaw's Heist steals a Kona, Rescue Beastie or Marang River Regent and turns their threat into yours. Oildeep Gearhulk and Malboro are too slow, Archenemy's Charm is mana-intensive, Wan Shi Tong is too passive, and Harvester of Misery has no relevant creature targets in their spell-heavy list.