The armor can only do so much to soften the blow. As the unnatural blades of wind flies towards him, Luca places his sword up. This is more or less a futile gesture considering that there's little way a man can "defend" against wind itself. His skin is sliced and gashes are made, but those start regenerating thanks to the body of a Heroic Spirit. With the spell cast, however, the wolves can better target Levin. With a howl, they summon eldritch lightning to strike at the spots Levin would most likely run towards hoping to hit him that way. It's ridiculous to try to aim for a moving target as fast as Levin, really.