Dimir Aggro is full of cheap noncreature spells (Thoughtseize, Fatal Push, Bitter Triumph) and tempo creatures like Moon-Circuit Hacker and Faerie Miscreant, so Magebane Lizard both blocks their 1-2 power creatures all day and punishes their spell-heavy turns with direct damage. Doorkeeper Thrull is an efficient flying blocker against their small evasive threats and shuts off Floodpits Drowner's enter-the-battlefield trigger, so it can't tap down or stun one of your creatures. Torch the Tower loses some value since their creatures (Sheoldred aside) are mostly small and efficiently removed by their own removal before combat matters, and Voldaren Epicure trades down into their cheap removal suite. Prioritize proactive pressure and blocking their small evasive creatures while keeping Fiery Temper available for Kaito.