Three potential abusers of Guinsoo's Rageblade, why nobody plays or mentions them?

1. AD

Since the last nerfs, people stopped playing Fizz AD. He can still be used, but it is not as strong as before, mainly due to no longer having the physical damage amplification on his ult.

However, with Guinsoo's Rageblade, I feel that AD Fizz can be very strong once again. Of the three champions I mentioned, Fizz is the one who can best abuse the AP part from Guinsoo's Rageblade. To the point that I start with , purchase , then I play him like his AP counterpart, until mid game where I start to transition to AD.

The trade off is that Fizz is the least tanky out of all the three potential Guinsoo abusers, and he also lacks self healing. He can use a Blade of the Ruined King, but the lifesteal on this item is very small, and this item is used mainly due to its on-hit effect that allows AD Fizz to be almost impossible to itemize against. Also, Fizz is mana reliant, unlike the other two potential abusers.

Suggested build:

With cooldown reduction runes and the above build, you can achieve 40% cooldown reduction, which is very good for Fizz. Unlike other Guinsoo abusers, he benefits a lot from cooldown reduction, mainly due to his E which will have a 5 second cooldown at max rank with 40% CDR. That's why I use Spirit Visage, too, despite the fact that Fizz lacks self healing. You can use instead for more utility for your team, but Spirit Visage offers better "selfish" stats.

2. 

He has never been popular, except back at the time he has been released. One of his main problems is the fact that Aatrox is very easy to itemize against, just by stacking armor. He lacks good on-hit effects, and he can't afford to purchase armor penetration because all armor penetration items lack synergy with him.

However, Guinsoo's Rageblade can solve this problem, by giving Aatrox an on-hit effect that is magic, making Aatrox very hard to itemize against. He can also have better dueling potential and, although he can't abuse the AP very well, he can use it to a good extent due to his E and his ult.

The upside is that Aatrox has the best sustain out of all three potential abusers, and he even has a free in-built GA. The downside is that Aatrox has very poor base stats and his early game is quite weak.

Suggested build:

3. 

I don't even know why people don't use her. She is one of the best potential Guinsoo abusers, due to her natural tankyness, strong early game, lack of resources to spend, and lots of in-built magic damage. She even has some percentage magic damage.

The downside is that Shyvana is the least disruptive out of all three potential Guinsoo abusers, but that's the only actual reason that can justify not using Shyvana as one of the potential Guinsoo abusers. As I said above, she is naturally tanky. Her sustained damage is one of the best, if not the best out of all Guinsoo users. Her auto-attack reset on her Q allows her to stack Guinsoo faster, and the AP isn't wasted either due to her E and her ult. Shyvana's amount of magic damage makes her extremely difficult to itemize against because even if you build magic resistance, she still has a lot of physical damage, due to Q and her aulo-attacks (and possibly Blade of the Ruined King).

Suggested build:

You can also use instead of Wit's End for more % damage and a physical damage source, as well as lifesteal. Generally I prefer to use Wit's End, especially if I am against an AP champion in lane. Mainly due to the fact that the % shred allows me to obliterate squishies. Also, it is cheaper and easier to build. Blade of the Ruined King, on the other hand, is better against tankier targets, or against very mobile teams.