I sincerely don't know what should I think about these nerfs...
On the one hand - I love Viktor and, in my honest opinion, he doesn't deserve nerfs. His obnoxious burst is balanced by lack of CC, range or mobility that is so easy to abuse. Can anyone enlighten me why noone cried about how OP he is half a year ago? Or why people abused me for picking "shit champion" when I could go OP Xerath or OP Zed? Literally nothing, besides a few bug fixes, changed since his rework. NOTHING. Then why suddenly he received so much hate?
On the other hand, soloQ mirrors LCS hype. At least in higher elo there is a tremendous amount of people banning (he bears 22% ban ratio right now in Plat+ division) or picking him just because FotM. I was able to pick Viktor every time I got mid all the way from Silver to Diamond; now I am basically not able to play my favourite champion anymore (got to play him in soloQ exactly 9 times during the last two months) and I am forced to watch all these petty meta humpers that pick the champion not because they love the champion, but because a few Korean pros won a LCS game as Vik. And it makes me furious. I hate that attitude and I hope that all these guys will dissappear in a cloud of ashes after the nerfs.
Now about the nerfs themselves. I was actually prediciting Hex Core nerfs. The thing is, that in 5.13 patch the core AP items got changed and HC was left untouched. That indeed made Viktor a bit stronger than before, especially combined with the additional 5% AP from the reworked Rabadon. Let me copy what I wrote in another thread on another forum
When max-maxed, Hex Core gives 168 AP. Even before that point the item is insanely strong, especially when combined with the buffed Rabadon. Let's say you've got both Hex Core mk-2 and Rabadon at level 13. It's 5500 gold "build", giving by itself (120+105)*1.35=304 AP. When we take all stats into consideration, we have 5500 gold "build" with stats worth of 7202.8 gold without even taking the two ability upgrades into consideration. Congratulations, we just saved the NLR+Amplifying Tome worth of gold and still have more AP from that.
Everyone knows how beautiful Viktor scales with AP. When we'll take also the standard runes/masteries/Doran into consideration (what leaves us with ~380 AP overall with two items build) we can clearly see that the very existence of Hex Core just dooms him to powerspike a bit harder than other midlaners, even when he isn't going the glorious Rabadon rush build.
So I understand why their nerfs address particulary Hex Core; however, I don't think they did it good. If they did it right, they would just put it on par with other AP items changes so he reaches the state before the 5.13 patch. But that nerf is... Well. It's bad.
Firstly - his early game isn't as good as people make it out to be. Sure, he has his shield. But he doesn't have range. He doesn't have CC nor mobility. It's so easy to abuse. Early game junglers, that are out of meta anyway, make his live living hell. There are a lot of matchups where going into AA range is just, let's say euphemistically, a very bad idea, sometimes lethal even. E upgrade allowed him to farm safely from range what was sometimes his only way to defend himself against likes of Fizz or LeBlanc. Now rushing E upgrade will make him more harm than good. Any of you heard about Ahri's Q syndrome? Yeah, that's exactly the fate that Viktor will meet. Leaving the minions with ridiculously low HP so last hitting them in any way becomes impossible. Since only two of his basic abilities deal damage he will lose around half possible CS in unfavored matchups and he won't be able to do literally anything about it.
It seems that I wrote a huge wall of text so I'll stop here. I'll just add that I miss the times when you met another Viktor and could be completely sure that he is a main. It didn't happen too often but the amount of roleplays made was unbelievable. And now? It's only FotM. I hate to see my beloved champion nerfed but well... I'll take it if it only will elliminate all the pathetic meta humpers.