Lucian's attack ranges have gone down, but E's cooldown will now get reduced with every hit from Lucian's passive. E also has no mana cost, so Lucian will be dashing quite a bit in the mid to late game.
Our design philosophy when approaching a strong champion is to highlight their strengths while also emphasizing their weaknesses (I told you we'd be repeating this a lot). This mostly relates to the concept of meaningful choices, where we want that champ to maintain their strategic value while also having some tradeoff that enemies can play against. Specifically for Lucian, his high generic power (a strong early and late game, high burst, high mobility, etc) meant he could just be blindly picked without much consideration for the enemy team. For a while, this is what made Lucian such a strong competitive pick - he could adapt to any team and could still perform well.
Ultimately our changes are focused on highlighting some of Lucian's strengths as a spell-slinging, mobile marksman, while also emphasizing new weaknesses - like having a lower range. At higher levels with some items (cooldown reduction!!!), Lucian can fluidly chain Es together as long as he has a target to hit with his passive. This also means Lucian will be one of the most mobile mid-range ADCs in teamfights (there are some concerns that he'll be... too mobile thanks to E removing all slows, but we'll keep a close eye here). Having a lower range, however, also means Lucian will need to take more risks in order to get E's cooldown back up, and he might have some tougher matchups during the laning phase (where before he could win almost any lane). This gives us a lot more space to emphasize Lucian's unique traits, and we'll be watching how he performs after these changes.
General
ATTACK RANGE 550 ? 500
BASE MOVEMENT SPEED 330 ? 335
BASE HEALTH 470 ? 500
BASE ATTACK DAMAGE 49 ? 52
Passive - Lightslinger
THE DOUBLE TAP RULE Fixed a bug where sometimes Lightslinger would fail to kill a champion because it incorrectly predicted that the first shot would be enough and would use the second shot to last hit a minion. Lightslinger will now always follow the double tap rule by shooting a near-dead champion twice to secure the kill.
Q - Piercing Light
NEWFARMCIAN Piercing Light now deals 75% ? 100% damage to minions
CAST RANGE 550 ? 500
COST 60/65/70/75/80 mana ? 50/55/60/65/70 mana
E - Relentless Pursuit
NEWNOW WITH MORE RELENTLESSNESS Cooldown is now reduced by 1 second per Lightslinger (passive) hit, doubles against enemy champions (2 second reduction per hit, 4 seconds total for a full passive proc)
NEWNOW WITH MORE PURSUIT 60/45/30/15/0 mana ? 0 mana at all ranks
NEWSMOOTH SHOOTER Lucian now resets his basic attack timer upon dashing
COOLDOWN 18/16/14/12/10 seconds ? 14/13/12/11/10 seconds
REMOVEDCULLED Relentless Pursuit no longer resets on kill during The Culling