From my eyes as a non-viktor player:
Viktor is either a hit or miss champ. If you get 1 kill early, you will carry your team no prob into late game where hopefully your team can still win as Viktor seems to fall off late game. Whether that be his scaling or the fact he only has 5 real item choices, I'll let the viktor players decide that.
To make viktor more appealing and useful to play, I would be looking for more utility in his kit. So far, I have only seen viktors get the augment that enhances his damage, the name escapes me since I never really played him more than the free week after he came out.
What I mean by utility: If annie doesn't get super fed, say maybe 3/3/8 and semi decent CS. She can do some slight damage late game but she has the spells and CDR to stun multiple times throughout a team fight if not focused. Viktor is kinda screwed since his stun/slow bubble has a long cd. Don't get me wrong, that bubble is OP when used by a skilled viktor, but misplaced, viktor may have just died.
Next, his shield from his q seems outplace, I mean its nice, but you can't just give viktor a shield, force him to use it to do damage when he either wont need the shield at all, or it is too late and he will die regardless of having a shield.
My suggestions(not all together, just possible changes):
1. Let his q go off without interrupting his movement. Slightly reduce the damage, just a bit to compensate. Will help with running around away and still getting a shield, similar to morg.
2.Give his augments second tier augments to make his late game on par with others. Have 1 build a second tier with more damage. 1 with more defense and 1 with more utility.
2b. The attack and defense second tier augments would be kinda easy, just give them more Mpen and AP or MR and armor/better shield. But for the utility, maybe decrease the cd of his bubble and maybe adding a Blind to his ultimate. I mean he has no real defense from an ad carry/ad assassin other than a small shield and the game needs more blinds. Also makes sense that a giant electric storm right in your face would blind you.
3. Last and most obvious. FIX HIS LASER! It is impossible to play against a viktor when his laser is invisible half the time. =/
Those are my suggestions, from a non-viktor player. Just my ideas I could think of.
I have not read anyone else's idea, so if we have similar ideas, I did not steal them, I just was blabbering >.< good luck with viktor and the glorious evolution!