Hi, you might think i'm crazy or trolling with thiose weird lb builds, but actually I mannaged to reach mastery 7 by playin lb top and adc.
Leblanc got a great panoply of skills, whith mobility cc and high base damage, everything can be done with that kind of champion.
Obviously, these builds works according you master lb well enough to brain your oppenent, so on it is not advice to play it in ranked before you already tried it as the play style is very different on each build.
And keep in mind that they don't use to play against this kind of lb so they will be surprised (I took a kill 1v1 against a chalenger lee because he didn't realise I was ad and had hexdrinker, he was definitly better than me, more fed, but my build surprised him)

First, all lb players have already been frustrated when an enemy survive to your combo and is still root, you want to kill him with your aa but you just got no damage.
Then your W can be used to move around the fight instead of dealing damages which make you unpredictable and gives you a safer gameplay. (you can juke them without losing 1/3 of your damage)
Your roots make you able to dominate most of melee champions.
YOUR CLONE CAN USE HIS AA AND DEALS THE SAME DAMAGE AS YOU. (Try to use your ult for the chain if you want damage, your clone will last longer and land more aa)

Early, try to freeze your lane as at lvl3 it's a free kill on gank as you can root, play safe enough to be healthy when your jungle ganks

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CARE as an adc, early your spell damage are enough, but your aa are quite weak in mid-game before you got infinity edge. (you will probably be more usefull at splitpush meanwhile you are in this situation)

First, lb isn't able to instant depop a carry like in S6 excpet when very ahead. So, playing tanky is a way to secure your root and your passiv proc to optimize your damage.
Secondly, if the ap ratios make of lb a great assassin, her high base damage on spells make tanky builds viable on her for a more constant damage.

She now got a good cleaning speed (new aoe combo+more little monsters in some camps)
She got control, ranged aa so she can easily kite buffs and kill the crab.
She got a huge mobility, control and burst for insane ganks
You can faint you are ganking with your ult without missing farm because you don't want to be spoted (if they don't have vision in your jungle), you can save lifes by fainting the couter gank.
You can easily faint a backdoor at lvl6 while you are coming from your side, new "sandwich" leblanc

Tip: if they got flash dash in and launch your Q first they will probably flash if they think that's the E, then root them

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CARE you're very easy to counter jungle, and to kill if you are in cd (and you will often be in cd while farming), try to keep your jungle warded.
CARE don't max your E at lvl2 except if you are 99% sure to take the first blood for your team. You will get in trouble to farm before lvl3 (if you do that try to kill the blue and the gromp to reach lvl3 as they are solo monsters and you will can kite them)

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Jungling:

Begin at the red then you can take the birds as you will deal good damage on each (that's a pretty good thing that you can take birds second because classic jungler often invade these one before to gank), then take the crab for health (if you want to do it this way ward early there blue side to make sure he isn't on you when you do the crab), the ennemy jungler shouldn't be there already(if he starts red), then look for a gank or do your blue side jungle.
If he starts blue just do a classic cleaning, to make sure he doesn't invade your blue(and if he does you will definitly be useless for a while)

You got quite good base damage, so on you are still usefull even while late in gold and with supp items.
You got a good mobility and can optimize a supp item active capacity.
You got some control. (You can control both of the botlaners during a gank if well played)
You got a great utility global ultimate which can be used to :
-Check drakes or Nashor
-Spot ennemies into the jungle
-Faint your ennemies and make them waste some spells and summoners, or make them come to your teamates, even with a good vision they often don't realize that you can't be there as they are threatened(only works when they are scared by you for exemple when they are low)
-INTERUPT A SKILLSHOT, OP AGAINST SOME ULTIMATES (RIP graves, ashe, jinx, draven....... ults) OR GRABS.

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CARE you give no sustain to your adc, your root is your only way to protect him before you got supp items.

NOT EVEN FUNNY...
A lot of guides will explain you how to play classic lb better than me

Just an advice : for all champs which got a dash and a skill shot(arhi, lee, lb, ezreal,...) if you dash in his direction he will can avoid either on the right or on the left, 50% chance to hit. And as you probably don't like to need luck, dash on a side, but still in his range, like that he will got only 1 way to go as you are on his right/left he can only walk back to avoid it, so lauch it a little on his back (if you know he is good enough to try avoiding it, obviously, you don't need it in bronze)

This video explain it with more details : https://www.youtube.com/watch?v=hTjfnTuLCAs