WBR is an aggressive midrange deck full of small efficient creatures like Marauding Mako, Iron-Shield Elf, and Hardened Academic, making Slagstorm's 3-damage sweeper mode very strong against their early board. Spell Pierce is well-positioned since we're the deck trying to stabilize and their noncreature spells (Cool but Rude, Requiting Hex) need to resolve cleanly to be effective. Spell Snare and Get Out are cut since their curve skews toward 1-2 mana beaters better answered by a sweeper, and countering a creature or enchantment spell is less impactful against this aggressive gameplan. Keep the full core engine, leaning on Hearth Elemental and Eddymurk Crab as blockers while we sweep the board.