Hi. I am not good at creating build,but i wanted to share this cool way to play Jarvan IV.
Please rate and comment what do you think about it. Thanks.

I played Jarvan IV not for long but i found awesome build. With this build its really fun to play. At the begining when u take armor and five hp potions you can farm minions for a long time. when u get wriggle's lantern u can go to do some jungling. Kill golem for mana and cd reducion buffs. then u can go easily kill enemies. After i buy mercury treads they provide you some speed and survivability. Banshee's veil gives you good passive effect and gives you some hp and mana it is very good. After i get some damage and lifesteal. And then you are very strong in team figts and alone.

I take exhaust and flash. Exhaust is very good and fighting and trying to escape. Flash is useful to catch enemies and escape. You can combine flash and ulti for a perfect escape. Just use ulti on enemy and then flash out.

I take armor penetration, attack speed and health. Armor penetration is very good because you deal way more damage. It is really good at the begining. Health is good at the begining too, it gives you good survivability and you can kill enemy easier. Attack speed runes is good because u get a lot of damage so speed is very awesome.

For masteries i take 21/0/9. From offensive i gain some damage, damage to minion, it's very good at begining to farm. in utility i take hp and mana regeneration it's effective. And it's good when your golem or other jungle minion buff is longer.

You start playing with armor cloth and 5 potion. You take demacian standard. At level 1 you better no harras enemies with your demacian standard. Keep it when you can combine it with dragon strike.try to last all the minions. Because of passive you hit a lot to them it is easy to last them. After you wriggle's lantern go to the jungle for some buffs. And when you have low hp you can go to jungle lifesteal it. with buffs you can harras a lot coz your cd reduced and mana regain increased. Dont be afraid of enemy if you both have low hp, you can kill him. Of course if he is not feeded like ****. Using demacian standard and dragon strike you can run or catch enemy jumping the wall. That's it i think. I played Jarvan IV not much, but later I can out some score pictures here.