Pros
-High Burst
-really mobile
-tons of lifesteal
-tons of AOE DMG
-tons of FUN
-DEMACIAAA


Cons
-really squishy (so u need to know when u can jump in)
-easy to focus
-needs to hit his E and Q Combo
-he is meele

So its not the normal tank J4 as u saw so which lane is he best suited for. So if u ask me i would tell u u can play this guy everywhere. U just need to know how, like in midlane u farm and harrass with your q and against most champs u can try a little all in at lvl 2 with your E and Q Combo try to do that if the Enemy goes for an lasthit so u can secure that your Combo hits and somethin good to know if u play midlane is that if u face a lux or morgana with a cage, u can still use your E and Q Combo while u are caged not like other mobilety spells. Allways remember aswell that in midlane u mostly wanna push your lane so u can go Roame and help your jungler bot top...
If u decide to play this awsome J4 at botlane u have to be really carful at the few first lvls, cause u are just meele and your enemy is ranged mostly u just wanna go for lasthits if your q is ready so u can harrass them back if they dare to touch U the mighty prince of DEMACIA, but as soon u see a good time to hit your combo and go all in on them without taking too much minion dmg u should do that and as soon u hit 6 u can make them explode anyways with your manliness.
If u play this Guy top lane however u have to be garful about your enemy building Armor, Armor is your biggest Enemy and u might have to build your Last Wisper earlier then u want, and if u are loosing your lane hard u should just go build tanky like all the other boring J4 players so smash your enemy and have fun ;)
So then u can play him in the jungle which is pretty normal but u just buy the machete and never build anything else out of it cause u will need your money for your Hydra, if u jungle this guy watch that u kill steal some kills at begin of the game, don t worry your team will be happy if they see u DEMACIAAAA and kill the whole enemy team allone but never forget that after u got a few kills u might should let some for all those other noobs in the game cause u don t need all of the kills ;)
As Support Carry u also wanna get some early kills ofcourse but after that let some for your adc aswell if he doesen t suck ofcourse. then u build sighstone instead of the last item and you will be fine

Allways Remember that J4 has one of the WORST lvl 1 from all champs in this crazy League. so never try a all in against someone at lvl 1, ecept he tries to towerdive, or fight against u while u have huge minionwave, then u should fight back.
Well now comes the good part J4 has the worst lvl 1 but for that he has one or even the strongest lvl 2, jarvans lvl 2 combo has a really high burst and just a few champs from the league can trade against that (ofcourse we assume u hit your Combo) however there are some which will fight u back like Lee sin, Xin Zhou,maybe Riven and a few others. but u can still even win against all of those if u outplay them. they just have the cahnce to fight u.
Basicly this means u try to get as much lasthits as u can and harrass them a bit with your q so u can jump in and kill them as soon u hit lvl 2 :D

Well this is something i should show u guys with videos, but cause i have no clue how this mobafire site works and i have no clips anyways i will give u a short explanation.
The Lanemomentum is about the minions, so who has more-less minions who is pushing and who gets pushed. So basicly allways if u get countered no matter with what champ or lane u can Push your lane and u will have free farm or even win your lane, cause the enemy can t fight u while u have a bigger minionwave cause if he will he will end up getting tons of dmg from minions and die.
However there is one problem about this whole thing which is called the Jungler cause if u allways push your lane and u have no wards u will be like something to eat for the enemy jungler, short said u are like Candy. So guys allways remember if u push your lane cause u wanna have free farm and kill your enemy never forget to WARD!!!

When do u Push or Freeze your lane?
You wanna push your lane if u wanna fight your enemy laner, if u killed your enemy laner or if he backed

You wanna freeze your lane if he backed and his lane is allready pushing, if u are sooooo much ahead that u can even fight him if he has a huge minions wave so he get 0 farm and if he want u can just DEMACIA him to afterlive or if he destroyed your tower and u are sooooooo far behind and u just wanna farm

If u use your autoattak allways if its off cooldown and your Q and E combo or just Qto kill the minions u will automaticcly push your lane like a boss :D

if the Enemy lane is allready pushing and u just hit the minions at the very last time u can freeze the lane or just push it really slowly