Arcane Barrier

You create a magical wall of force in the hand holding the material components or the arcane focus used to cast the spell.  While the spell is maintained you gain a +2 to AC. This counts as wielding a shield for all purposes. This includes things like required shield proficiency, not having a free hand for somatic or material components of other spells, or a monk’s Unarmored Defense.  The spell can be ended by the caster as an action.