Pros and cons
PROS: Very good team player and can solo too
Good passive and abilities
Combo from E and Q
Good harassing possibilities
Most beautiful ult Cataclysm in the game
Can be as tank or as AD-offtank
CONS: Can be easily killed when his abilities are on CD-s
Very mana-hungry early game
Ult can work against him and his team.
Jarvan as Offtank AD and his skill sequence.
I like playing Jarvan since he came out. He can nicely work in cooperation with many champions, for example Nocturne or Blitzcrank. He can be easily played as a jungler. This is a laning guide, not jungling guide. At starting, Jarvan has a good amount of health, and he is strong at making damage, but his mana is low. When he reaches lvl 2, Jarvan starts to be strong with his combo (but runs out of mana quickly, unless you don't spam your spells) . It is like a shock weapon to enemies and it does alot of damage. When I reach lvl 3, I will upgrade my Dragon Strike because of it's slowing effect, but the shield is sometimes good too (someone ults you). After lvl 4 I upgrade my Golden Aegis because of it's solid amount of dmg. I upgrade my ultimate al lvls 6, 11 and 16. First I max my Q, secondly my E and thirdly my W.
Runes for Jarvan
Quints: I take Quint of Attack Damage because then I can do much early game damage. It doesn´t give so much boost after, but when you can farm good early game, it gives more boost than any other runes.
Marks: I take Mark of Armor Penetration because then I have even more damage output with my armor penetration. These are just good runes.
Seals: I take Seal of Armor because i want more defence against other top-laners (almost always AD). It gives me great boost, because enemies need to spend some gold on armor pen. when i have these runes.
Glyphs: I take Glyph of Magic Resist because I need good counter against AP-casters too. It gives me a good advantage over enemy AP-heavy champions because I can counter their damage better then.
Masteries for Jarvan
My masteries are 16-14-0. It contains both attack strenght and survivability.
My offensive tree contains bonuses for summoner spells, AD, Attack Speed, Crit Damage, Armor Pen and more damage.
My defensive tree contains HP, Armor and Magic Resist. Nothing to explain there. I just need those things to survive better.
Farming minions and harassing/killing enemies
In early-game I last hit minions with my physical attacks, but when my Q is getting stronger, then i can farm with my Q too. Sometimes I take out full minion waves with my Q. Dont forget to LAST HIT minions with your basic attacks, Jarvan IV makes it even easier because of Martial Cadence
Early-game harassing is with Q and E, but not with combo. You do combo when you want to take out that enemy. Sometimes I get kills when I am level 2 to level 4 easily. When it happens, I can get kills every time I want because I am getting alredy fed.
Killing spells: E, Q, W, E, Q.
After lvl 6: E, Q, R, W, E, Q.
Both times enemy will be dead or seriously injured, that you can kill them with 1 physical attack.
Martial Cadence (passive) - A very good passive, does a percent of enemy HP as a damage. Very good for harrassing enemies.
Dragon Strike (Q) - Good amount of dmg, nice passive at enemies and friendly range too. Gives a good boost in your damage and works awesome with your E
Golden Aegis (W) - Good shield, but doesn't block a lot of dmg. I take it because of slowing effect, but at lvl 5 the shield is good too. In teamfights it is ******* how useful. It gives bonus shield per nearby enemy.
Demacian Standard (E) - Bread and butter for Jarvan IV. Gives attack speed, armor and makes a nice amount of dmg. It is the second part of his Q and E combo. Good is this, that it gives AS and armor to all nearby allies and it works as a ward too that you can check bushes with it.
Cataclysm (R) - Most beautiful ultimate in game and it does solid amount of damage too. It can be a most useful ultimate in the game, but it can hardly work against you and your team. You must have right timing to make arena or to collapse it. You can block enemies from escaping, but don't use it at enemies who has summoner spell flash or has built in blash or some kind of dash/jump, but with this build you doesn't have to fear that, your spells are doing great amount of damage already and you can follow them with your E and Q combo, that probably already kills them. If not, few auto attacks and enemy will be dead.
Champions you don't want to lane against
All stealth champs - Just can make his ulti kinda useless, exept when Jarvan has Oracle's Elixir on.
All jump/dash/flash champs - They can escape his ulti and they can turn Jarvan's ulti against him.
Flash is your worst enemy in game.
This is my first guide and I just can't put pictures or videos in it, you can comment or help me to make it better.
Don't downvote if there isn't any exact reason to do it.
Comment and always say if there is anything wrong in this guide. I will always upgrade and update it and I will answer your comments if you ask me to do it or if necessary or if I want to do it.