Hey Guys!
I'm KentaruM, just your average casual player. So one day I saw this little tidbit on a new LoL character to be released..... and I was hooked. I waited eagerly for this character to be released. And then finally, He was!
Enter Lucian, 2-gun toting slayer of all evil!

Now I usually hop right on Moba here to see how to work a new character. But, alas, no build yet existed! So after much gameplay and research i came up with my own. Content to just sit back and let it be I never looked for a guide again. Then a fellow summoner asked me what build I followed. When I said my own I was told to go check out the new builds and see how they compared.
I didn't favor too many (not many up yet) but I did like Rohu16's build =) However, I figured it was time for me to toss my own out and maybe help a few people.
Take it easy on me! This is my first custom build!(still working on it section by section)

Pros Extended Range via Piercing Light Sweet Chase with Ardent Blaze Awesome Passive gives you insane stacking power! Built in slow break

Cons Mana Hungry Skills take some getting used to to land hits Ult easily countered by move spells. IE Flash Slow starting attack speed

SO for my runes I use a pretty standard AD carry build.Now If you want you can swap out the Greater Mark of Attack Damage for greater mark of armor penetration AND the Greater Quintessence of Life Steal for Greater Quintessence of Attack Damage
I use the Marks of Attack Damage for great early-game power. If you prefer a late game increase, you can go with Armor Pen. But Be Warned! If you grab the right items the Armor Pen boost from Marks is overshadowed by the items!
And if you think you can survive without that Life Steal, Go for it! 3 quints of Attack Dmg will give you an additional 6.75 attack at start!

OR you can put them into another slot if you think you can survive without that little boost. I encourage you to customize this build as you see fit!!!!

Now for the Hot Topic: Items.
Kentaru, what are you thinking?!?!?

Well, the items here are built to max out your DPS BUT they are not mandatory! This is what I am comfortable with using. Tweak it to your hearts content!

Start!

A pretty standard start for ADC. This allows you to trade a little longer in game thanks to that life gain and extra life. Sell this once you start getting full inventory and you have Bilgewater Cutlass or you need that extra little cash.

Long Sword + 2x Health Potion gets you started on that Vampiric Scepter I use this if I have a viable support that can keep me alive. the Pots give you a nice emergency pop of health after that unexpected smack.

VS

So why do I build BotRK over Bloodthirster? Well for me I want that extra little attack speed boost to beef up my ult and that 5% current health bonus helps knock down tanky targets quickly. HOWEVER, Bloodthirster is most definatly a viable option! Quick farming grants fast stacks. More stacks=More AD. More AD=More Kills.
THe choice is up to you!

The Rest of the Lineup

Since attack speed is Lucian's best friend, these boots fit right in. Later on in game you can beef these up with enchantment; furor (for chasing down those tricky runners) or with Enchantment: Alacrity to get between lanes faster.

Again, attack speed is your best friend. But in this case, so is Crit. Crit gives you that extra oomph in your burst, it also gives you an attack speed bonus via Frenzy

So do you like to shred your opponents armor? How about casting more often? If you answered yes then this is the weapon for you. To make it even better, your passive makes this stack VERY quickly. After casting a spell your next basic hits twice... immediate 2 stacks!

This is an interesting item. After you build up your full stacks of Mana Charge, it turns into Muramana. the extra mana helps with Lucian's hunger and the bonus attack damage is very nice. However, early game Tear of the Goddess does not provide much. I would love to get this every game but sometimes you need that extra health or that little bit of shred.
***ABOUT Muramana***
Muramana's active is very neat but can shred your mana VEYY quickly. Every shot takes 3% of your current mana to deal an additional 6% of your current mana as physical damage. USE THIS WISELY. Like Ashe's Frost Shot, only use this versus champions. Unlike frost shot though, you can use this against towers to burst them down quickly.

Passive

After every ability you use your next basic attack becomes a double shot with the second shot doing 75% damage. But it does full damage VS minions. Very strong passive that applies stacks like Black Cleaver and red buff quickly.

Q

piercinglight Lucian's main ability. It scales very nicely and has a pretty long range. The trick though is that you have to have a target to use it. No random shots there! But this shot flies the whole way through all targets in the line so use this to hit someone outside of your range zone by hitting a minion in front of your target.

W

A fun little ability that gives Lucian great chase and escape when used correctly. The cross shaped explosions takes a little getting used to though. But once you get the hang of it you can use it to pick out and pick on your target. Also learning the range on this is a must. It explodes upon contact with the first target it meets OR at maximum range. Use the cross to hit a target behind a minion OR beside one easily. Fire around mobs to have it explode behind enemy champions.
The second part of this ability is what gives you the chase/escape. Targets hit by Ardent Blaze recieve a debuff that when you strike them with another attack, you gain increased movement speed. If you really need to chase down that coward and he is out of range of your shot, Hit some nearby minions with Ardent Blaze then a basic, get your boost and chase him down!! Is he chasing you? Pop him or some minions with your blaze, get your boost and Advance With the Enemy (AKA run away!!!)