Ok, Pyke is not ok.

You're running on outdated news. Pyke's ult scaling got slashed from 140% scaling down to 60%, which makes it much more realistic for the game. Plus, it's not like he's going to be getting gross amounts of AD, because the HP to AD conversion isn't that high.

The HP -> AD gold conversion is slightly worse than buying AD itself. He'll be fine.

he cant scale health

The only thing that needs a little nerf is his ulti, but he is pretty much perfectly balanced.

I think that passive is stupid. You can buy Randuin's, Adaptive Helm, Righteous Glory, etc... to have really good defenses and utility but still get AD. And as long as he has such massive base health, the loss of the health from those items does not matter at all. It just limits his ability to facetank. But it still allows him to be a lot tougher than other assassins.