User blog comment:Willbachbakal/(Champion Concept) Skjold, the Shield Warrior/@comment-5088437-20130121012315/@comment-1330314-20130126012841

Considering Ez and Nami's ultimates are both larger than the spell shield, it wouldn't block the ability completely. Laying down a barrier preemptively wouldn't be that much more complicated than setting up a spell shield anyway (in fact, it'd be easier).