WU leans on Stifle and free counters like Daze and Consign to Memory, plus Teferi, Time Raveler to lock us out of instant-speed interaction; Lavinia, Azorius Renegade shuts off their Daze/Force of Will/Consign to Memory unless they actually pay mana and taxes their noncreature spells. Flusterstorm helps us win key counter battles over our Brainstorm or Dread Return. Shuko is weak against a deck full of removal like Swords to Plowshares, and Orim's Chant is redundant with the disruption Lavinia already provides. Watch out for Wasteland pressure on our single-copy utility lands.