Well that just sucks : c 

Though I can think of various different things that can get around it. Any magic that involves launching objects at him such as Geomancer throwing a rock at him or electromancer using metal flechettes via magnetism, any non magical projectile attack that he could see. hell, if multiple enemies throw magic bolts at him, he is not likely to deflect them all. As I said, the sword only deflects if the projectile makes contact with him. 

And if a magical barrier is particularily powerful and not conjured by some half-assed mage, the sword will cause haklo excruciating physical and mental pain.