Lucian
Attack speed per level lowered to 1.5 from 3.3
Lightslinger (Passive) second shot can no longer critically strike
The Culling (R) [previous damage reduction and change to allow R to crit REVERTED.]
Now crit builds are less viable and armor pen is the way to go.
God In A Condom4 voteslmfao lucian needs a nerf, hes been the top adc for a while now. Pretty much if you want to win bot lane you had 2 pick lucian. This nerf was needed so other adc could be pick and not just have 1 that out shines them all
archerno11 votesWhich is good considering all those tanks
Erockandroll1 votesI Could imagine that his ult is just being retooled. Having his ult scale with crit chance sounds like a pretty good way to support him with standard ADC items. Until you remember that ER exists. And with like, it would probably have lead to some pretty bad patterns of Restoring your Mana by ulting. (Especially since ER also ensures you will have max CDR.)
This may also explain why Riot is removing the crit from his passive, With the ER build, he's simply not being mana gated enough. If they are going to put crit on Lucian's ult, they probably need to do so, without it interacting with ER.
Espy Psyche1 votesI'm really hoping these changes will make "blue build Lucian" a thing.
C9 Squeeky 1 votesblue lucian can be a thing without these nerfs. This just forces him into it
LeaguePatrol1 votesits either him or they gut fighter items 
that hes abusing right now. the nerfs to his attack speed is probably to make this build not as viable over the traditional adc build. but the crit nerf seems pretty harsh when he is losing more then half of his attack speed per level, then again no one wants to play against build, good riddance