I think Fizz's W could use a complete rework

Title.

When Fizz builds as an AP assassin, his W serves only to increase the base damage of his Q with no actual gameplay involved, and this is on a champion who's assassination pattern already has significant counterplay issues.

When he builds as an AD bruiser, his W makes it incredibly difficult to itemize against him because of the hybrid damage, as well as making it incredibly difficult to actually duel him because of the missing health damage.

Why don't we just rework his W into an ability that actually has some gameplay. Maybe a line stab skillshot that leaves the current Q dot on people it hits. Some of the damage from his E could potentially be moved into it, which would make him a lot less aggravating for many players because his untargetable dash wouldn't be as big of a nuke. The whole thing could actually be done as a buff to AP fizz because he'd have more reasonable counterplay now so buffing him would make more sense, and bruiser fizz would probably end up dead, which is a good thing.

Thoughts?

EDIT: Downvotes with no explanations? If you think it's a bad idea why not say why?