So yesterday, I decided to play attack speed Viktor, just for the kicks (Normal game with friends obviously), and after I got Runnans, if I Q a minion, then would auto a tower, the empowered auto would hit 4 or 5 times, instead of just 1. I did it several times to make I was not seeing things and it worked every time.
Vistha Kai2 votesThe effect isn't consumed on towers so it will be used multiple times.
Look: Vayne, Rengar.
Angelofchaos16x1 votesOhhhh ok, thanks for the info
Beerstein1 votesIt doesn't proc, just shows the visual/audio and the fact that it's not off cd yet.
Mannysmoker1 votesNo it doesn't looks like it does but no, is like 
he can use his W but the magic damage is not applied but he still the attack animation is the same until it goes on cooldown.