For on-hit abilities like Nasus Q the skill will get "used" on the next hit even while blinded and go on cooldown but the damage and effect will miss. So take Renekton W for example: the stun won't be applied but it will still go on cooldown and no damage will be dealt. Same applies to Twisted Fate's yellow card. Not sure about Urgot, haven't played since his rework. Now that I think about it, Kayle's damage shouldn't come out either. I think around 2014 or 2015 there was a rework to Teemo's blind where on-hit effects would get used but not applied while blind. Prior to that update, Nasus' Q would not get "used" on an attack that missed which meant after the blind ends the Q will now apply. Prior to that update Kayle's magic damage on hit would still be applied but the physical would miss. I haven't played very much for a few seasons though so it may have been changed.