I think Lucian's passive scaling needs tweaking
At the moment his passive just gives him free lanes. He puts the enemy ADC behind in cs and if they try to fight him he kills them or sends them to base. It's mostly because he wins trades so easily with his passive
His passive means he shoots twice on a basic attack after he uses an ability. The first shot is a regular basic attack and the second is pretty much his passive. The second shot deals 50-60% (Level, % / 1, 50 / 7, 55 / 13, 60) of his AD to champions and applies on hit effects (But does not trigger on attack effects like the 2 bolts from Runaans). I think that it's a bit too much damage early on to give his passive 50% AD level 1.
I'd prefer if it scaled from 45% AD level 1 and gave 1% per level, just to chip away at his dominance early on. He still has 50% AD scaling on his passive at level 6 (I made chose this because it means that his %AD is the same as before whenever he puts a point in R). It also gives him a more consistent ramp of damage rather than a free level up on an ability at level 7 and 13. The graph is here, I also put a line in for a 2% per level starting at 40% but I think that would just ruin his strength early completely, however it would make his strength more consistent throughout the game.
This is an overall nerf, most levels he'll be down in damage, but never more than by 5% of his AD, and like I said it's the same every time he puts a point in R so it's never very far off the mark later on, just during laning phase he'll be a bit less oppressive.
He also needs a slight reduction in armour if he's to drop to a mediocre level, but I really don't want him to be put in the rito balance dumpster for being a tad too strong atm. A lot of people are picking him up because he's strong and a fun champion to play, and I don't think immediate harsh nerfs are the answer. I think Lucian is a fun champ to have in the meta and he's healthy for the game, but right now he's fun at the expense of who he's against because of the dominance he has in lane, which I attribute to his passive, and so it should be altered as I describe, in my opinion.