Aatrox
Simply because it now only takes 2 attacks to proc his W, he will make fine use of the item. He also builds Bork, which is one of the most feared combinations with this item.
Diana
If it applies to Aatrox, it applies to Diana. While probably not going to be as popular, Diana can proc her passive much more quickly now.
Ekko
Once again, faster procing and, once again again, probably wont be as popular.
Elise
Double healing and such is really cool, especially when Elise uses her Spider Form W, giving her 30 (+30% AP) health every 2 basic attacks. Her spdier form on-hit damage will also be dealing decent damage as well. However, Elise usually wants to kill her targets instantly and not over time, so this might not be a thing.
Fizz
This is gonna be pretty scary. Fizz can now deal a lot of sustained damage in the jungle again, but AP this time. His W will be applied twice for 100 (+50% AP) every other basic attack. Some scary stuff here.
Irelia
The double true damage, double heal is going to be frustrating. Especially since Irelia buys Bork as well. However, still not sure if this is worth taking over another enchantment.
Jax
A BIG JAX BUFF HERE! His ultimate, if it's like Aatrox, will not proc every other basic attack instead of every third. This might not seem like a lot, but dealing 220 magic damage every other attack is pretty big in my book. Jax also buys Bork usually.
Kayle
Especially since Kayle is getting buffed next patch, she is gonna be scary with this. Every other basic attack applies her AoE, extra magic damage twice. Now thats just insane.
Kog'Maw
It's a good thing really he can't jungle, because otherwise this would be crazy.
Malphite
Not sure if it's worth taking over Cinderhulk, probably isn't, but it would be funny to see a Malphite be double procing his W every other attack for some cool looking sustained AoE.
Master Yi
May Rito help us all. Master Yi is going to need a nerf after this almost no doubt. Not only is he going to be charging his passive quicker, but his E will be applied twice. It doesn't stop there. Since his passive is another basic attack as well in one basic attack, his E will proc 3 TIMES every time he gets an enhanced basic attack, which will be more often due to Sated Devourer. Late Game Yi is going to be extremely scary. This item might change how Yi is built to become some on-hit effect god.
Nautilus
Same as Malphite. It probably won't be taken over Cinderhulk, but it would be very funny to watch in the couple games it works.
Nocturne
Makes his passive charge up quicker. Nothing major, but its an ok buff to the nightmare.
Riven
So, if you build up stacks as Riven, then her passive will be applied multiple times on one attack whenever Sated Devourer procs. While her ultimate is up, this is going to be a HUGE burst of damage. May not see the light, but its fun (or not so much) to think about.
Shen
Charges up passive quicker. Same case as Nocturne, except less impactful since Shen will still probably take Cinderhulk.
Shyvana
Eh, it might be taken due to her new W effect and her E, with it always procing if she uses her Q. It could be dangerous, but its no where near Yi level dangerous.
Teemo
If someone can get this to work, its gonna be near Yi level scary, especially since Teemo's other items are getting buffed next patch as well. Jungle Teemo might become a thing and I might start building Nashor's on him more often instead of burst build.
Thresh
Yes? No? Maybe...
Twitch
Twitch jungle? It allows him to fully apply his passive in 4 attacks instead of 6. Could see the light if it becomes popular. Might become dangerous if Twitch gets buffed. Would be cool to see how it interacts with his ultimate.
Udyr
Godyr rises. Tiger and Pheonix, no matter which, just became a lot more powerful. This gives Udyr three to four potential ways to build, being Tank, AP Burst, AD Burst, or On-hit. Yes? Is going to be pretty good most likely.
Varus
Double Blight? No, Varus cant jungle.
Vayne
Same as Varus.
Vi
An idea that probably won't see the light. Sustained W focused Vi that shreds tanks.
Warwick
While its been said it won't apply on his ultimate, it is still an overall buff to the wolf since his passive will now grow much more quickly.
Xin Zhao
Buff to AP Xin. Solo Tank more turrets. Cash. Profit. Heals for days.