When I got Jarvan, I tried a lot of builds and guides but none of them really got me any kills, so I gave up on him for a while. After maybe a week of other champions, I decided to go back to him, but this time with another build. I wanted to utilize his high damage at the start of a fight to severely cripple an enemy before finishing him off or getting the assist. This build is less of a durable Jarvan, and uses his abilities to their full ganking potential. Keep in mind that you won't have high health regeneration at the start, so don't be getting too risky.

When you play this build, it is pretty important who Jarvan lanes with. You can handle yourself fine with any champion assisting you, but there are better ones than others.

The best champion, coincidentally, is Xin Zhao. His fast attack speed and three talon strike make him perfect for slowing down the enemy as you both whittle him away with your attacks.

Any fast attacking champion and/or with slowing abilities is your best bet. You want to get off the the best start as possible, so make sure you choose wisely.

Doran's Blade is good starting weapon, some people may like to have a healing potion on you, but if you can harass the champions effectively, then you won't need to use one. Before going straight to the infinity edge or black cleaver, you might want to pick up a vampric scepter to increase your time in the lane farming.

If you want, you can also pick up a dagger. Infinity edge comes first (or sometimes second) because it gives you the damage boost that you need to stay one level above the enemies and keep them away from minions or waiting for their respawn timer to hit zero.

Black cleaver give you some insurance that any tank you come up against will not win in a close quarters battle.

Sword of the divine gives you more attack speed for quickly taking down champions and gives your lifesteal from vampric scepter (if you got one)more chance to drain.

From there you buy the bloodthirster, if you have your scepter, you use it in the crafting, if you don't then just more money.

After that you sell your Doran's Blade, this gives you a bit extra boost to buy your phantom dancer. This boosts your crit and gives you huge level's of attack speed. I believe it is 2.14 attacks per sec or something.

Then you sell your beserker's shoes and from there you can either choose another phantom dancer or madred's bloodrazor, depending if you're ganking, or attacking in groups.

It's pretty easy to use Jarvan with this build, the main difficulty is the situational choices. Sometimes, it's best to enter with a standard, then lance to standard combo. But at other times, you could be faster than the enemy, in which you want to save that combo for your escapes or chases. Golden Aegis isn't really that great until you get to level 18. The shield won't provide much protection, so you should use it for its slow ability. Try and time it just right so that when the enemy is about to escape, you slow him and get in those final blows. Sometimes you attack so fast and strong that it becomes a great opening move, to keep them from avoiding combat with running away.

As soon as you get infinity edge or black cleaver, all you need is a vampric scepter and you are set to take down most of the monsters. The dragon may be a bit too difficult. (i never checked, I find it best to just grab the golem and lizard buff and start ganking.)

Make sure that you use your Cataclysm at the right moments. If you are in a huge battle, trapping all the melee champions in an enclosed space with you may not be the best idea. If you are in a major scuffle, aim for the ranged. Once you entrap them, you keep the ranged in, and the melee out. To add on this, almost all of the ranged champions are fairly squishy, so you can take em down quick and maybe feed one some minions (if they are there) for some extra health.

You can also use this for chases. When there are enemy champions bunched together with some lower health, it can be really easy just to pick them all off inside the Cataclysm zone and rack up some kills. If you miss the group and only snag one, you can always cancel the spell by casting it again.

You can also use Cataclysm for an escape, but I'm sure you all know this. Just use cataclysm on the chaser, use the standard -> lance combo and escape the zone while the poor little person is trapped inside.

During a group fight, Jarvan can be picked off if you are doing too good. If they do they and choose you, then you are dead. This build does not leave any room for defense. Try and choose when to charge in and when to stay back. In group fights, the standard -> lance combo is very effective, try and aim for the most populated area and fire away.

So if you can give me feedback, it is greatly appreciated. Also, if you could give me some tips on improvement, then please do.