I've been summoned by Eye Ra and every time I go invis it cancels out the summon. If i don't go invis it summons me. So I don't think it is some of the time I think it does it all of the time while rap is invis. And I was wondering why the blades were so low of a chance to proc but now after playing it at a higher level they proc quite a bit. Out of 8 knife swings 3 effectively went off at level 1.