Ok tested it in a game, it doesn't proc your passive twice, sorry :/
But the build does a lot of damage though. After you've Q'd a target and you have your tears on, you're just bonking the target with your head right? Might as well bonk faster and do more damage with it. The interesting thing I found though was that the on hit damage from sated devourer ( 60 ), did more damage because of your passive. I was doing like 73 or so magic damage per hit even though I only had 60 magic damage on hit from my devourer. So this build CAN work, it does do a lot of damage, I melted the bots. Just doesn't proc your passive twice.