Dimir Midrange leans on The Wondrous Wasp, Enduring Curiosity, and Requiting Hex-style removal to grind through our threats, so Defend the Rider keeps our best creature alive through their removal package and lets us push damage. Soul-Guide Lantern disrupts Enduring Curiosity's return-from-graveyard value and denies any incidental graveyard synergy while giving us a way to draw a card later. Spell Pierce underperforms since this deck curves out with efficient creatures and has plenty of mana to pay around it by the time key spells resolve, so it and the top-heavy Terrian, World Tyrant plus a Lumbering Worldwagon step out for more resilient threats.