Pyke is busted, but no one plays him because it's boring

It's pretty much an open secret that this thing, this "Pyke", is blatantly OP. Then why isn't he played more often? Because it's boring. It's boring precisely because this shit's OP. Laning phase: hook, stun, rinse and repeat. Post-6: wait for the execute indicator, then press R a few times... which even resets. And whenever you fuck up, just run away and come back as if nothing happened. Besides, support mains don't find him appealing because he's an assassin (albeit with more CC than any other assassin). And assassin mains would rather play mid anyway. And you still need a decent ADC on your team to win.
So why is he OP?
The biggest culprit is the healing on his passive. Sure, you say that he can't get extra HP. But that is irrelevant. Does, say, Zed ever build HP? And is Zed able to convert extra HP into AD? Yeah, no. If you do the math, Pyke's HP to AD conversion is (almost) 100% gold efficient. What this actually does is make his abilities (and his autos) scale off of bonus HP and give him an extra pool of items that no one else has access to. And Pyke is the champion which needs extra HP the least, because of both stealth and that grey health bullshit.
The biggest threat when you're playing Pyke is letting all this OP get to your head, and throwing the game. I think nerfing him would make it a bit more challenging and fun, and maybe more people would play him. Start with that ridiculous passive. Maybe give him some kind of delay before the passive activates, like the 5-second delay on mobi boots.