(Note: This post is obsolete after Solcrushed reworked Viktor in V4.17. I still think the ideas below have some value as a potential different direction that could have been taken for Viktor, though his official rework is by far the better one.)
This is a tentative set of tweaks for Viktor, the Machine Herald. Viktor is one of the champions with the strongest themes in the game, one that permeates his ability set, but also one of the champions with the most wasted potential. While his active abilities are fine, his passive has a lot of problems: it feels like a debuff rather than an awesome item (you get locked out of a sixth item slot), the item itself doesn't feel that good (its stats and effects are sub-par when compared to a late-game item), and out of the three available choices, each designed to turn Viktor into a different champion with a unique playstyle, only one gets picked due to the better synergy with the AP/level passive. Effectively, he just needs a completely new passive, one that better captures the awesomeness of his Hex Core.
For this, I want to turn Viktor around: rather than have him be a five-item champion, I want him to be a seven-item champion, with the Hex Core taking a trinket slot. This Hex Core would be specialized right from the start, allowing Viktor to enter his lane of choice with the tools he needs to do well there and unlock more power as he plays. To compensate for this massive increase in power, I also want to pull some power away from Viktor's base stats: rather than be a jack-of-all trades, Viktor would become a specialist, outfitting himself with the exact setup of items he needs to fulfill his role to the fullest, with each playstyle featuring clear strengths and weaknesses. On top of this, I want to give his passive more interactivity, making Viktor's power growth reliant on proper gameplay rather than per-level ramping strength, and therefore allowing him to scale a lot more smoothly into the late game.
What are your thoughts on these changes? Aside from the rework to Viktor's passive, nothing else is really that different, mainly because I think his core playstyle is good. If you feel like there's information missing, I encourage you to take a look at the "additional info" tabs.