My NL has maxed lvl shadow web. I tried using it for fun in zakum against those brown flying mobs and it worked quite well in a hilarious way where they got webbed and dragged to the floor to be easily cleared out by melee attacker. However, blue flying mobs (both before and after they divide) weren't affected by the shadow web no matter how often I tried. I tried using it at Horntail against wyverns too but that didn't work either. It works perfectly well against almost every other, normal mobs. Is it meant to be like that? Skill description doesn't mention selective range of possible targets it can work on.