Greetings,

I won't go the same sh*t "READ B4 U VOTE". I clearly state here, in the beginning, I don't care about the votes. The creation of this guide was only made because I kept seeing people uploading Jarvan IV guides without even trying the character. I really don't know how they all made these tremendous games though.
Give feedback, cause I had some thoughts regarding what item should come out first from the ones enlisted here. Positive and negative comments are not my concern, I just want to let people see and try this guide. I explain every little item, rune, summoner spell and mastery selection I made and why is best in my opinion to get the full out of this char.

Best regards.

Here is a proof of recent games.

Pros
Lovelly 6 second auto spammable passive.
Pretty die hard char.
Can greatly initiate/escape a fight.
Dragon skin serves.
Ulti serves mid lvl opponents in tower range.
Can use ulti+ flag out to protect ally or u from dying,

Cons
Can block allies path with ulti misplacement. (between a narrow path)
Huge issue with mana.
He's a demacian.

3 Greater Quint's of Swiftness for the extra speed. Who doesn't want that extra boost of speed that will help u reach/escape? Stacks with masteries, items and ghost preeeeeety fine too.

9 Seals of Evasion for that extra dodge. C'mon I know u like it when someone chase you and Nimbleness procs because u just dodged that killing last hit. And it doesn't stop here, nimbleness will very nicely stack with ur starting boots + rune settup. If you die, you gotta try.

9 Greater glyph of Shielding. More cowbell pls. We all need end game outcome. Quit going greedy and chasy early game if you are not sure you will get the kill.

9 Greater mark of Desolation. This one was kinda hard to think but finally made me believe it's the best set of red runes for Jarvan.

I choose pikachu. But, in case you aren't level 40, you can pick Ghost with proper use, after u spam qweqweqweq (wtf random) a bit. Try to avoid popping ghost to escape, unless it actually worths evading an incoming death that would otherwise rend to the ground without ghost.

Second spell can be Teleport.
Ok, this little spell can help in soooo many things such as, placing a ward in a nice bush top/mid/bottom lane, when u fight in bot, go in bush hit teleport, insta change lane, let ur allies place a nice position for a stun, slow etc and spam ur imba heli-turbo-jet-pack to the air combo and get a couple of annoying kills. Pls don't be it assist.
Teleport can also help going back n forth like twisted fates BUT, without allowing others to know u did this. Eat that TF.

U can pick any other spells but I won't get into them. Pick any combo u like, I just give my best 2 options so there's no need to waste more lines.

I will only cover the important, others are self explained.
You need nimbleness to help u either escape, or make u run faster when u dodge someone in team fights. Stacking with seal runes and previous mastery path u have a nice dodge chance. Also when nimbleness pops, you got what it takes to run. Early game boots and runes to run like-a-zilean.

Overall the rest in defense tree is to help u being tougher to die. You will dish damage with your beefy char with the items you will make later. Trust me pug.

We put these 9 whole lot of points in utility mainly to reach the imba 1 rank in utility mastery. Im kidding u stupid, but hey, it's nice having +15% free time of a baron buff eyh? DONT U LIKE IT? WAHAhahahahaaa... -.- erhm..
3 in Perseverence cause you need early the mana regeneration and lately the health imba stacky regen. +ghost that stacks with all that bunch or speed u will have from runes n items.
+5% exp, yes I know you love it.

Ok this is the funny part. Get some pop corns.
Start with simple boots and 3 health pots.

When you got 1325 gold (if it's more than 1325 and u'r still there uninstall the game, paint your pc blue and drop it into the ocean to be never found), go b and buy asap your catalyst. Your char will kiss you every time he dings up.

Make your dodge boots to break some nerves with your speed every time u dodge.
Try to farm, jungle if possible, to make your impaler cause then is when the real fun starts.
Read again and again what this item does.

You did? Good.

Now read what frozen mallet does. OMG combo!
Oh it's not done yet. There's an item that blocks a spell every 30 damn seconds and it also combo with the 2 previous items. OMG Triple combo!!!11

Ok now if it's late and not yet done, make some lifesteal and convert it to cutlass for these annoying chars that like to ghost you away every time.

If it's after late game, make a PD (starting always from zeal), drink all the 3 pots and dance with the devil.

It's not always the best option to start with Demacian Standard + Dragon Strike combo cause your opponents will wait for that. Plus, they will know you have some time again untill you can disable them. Keep that stun to save some lives, possibly interupting a karthus ulti, a nunu ulti, you name it....

Ofc, when you wait in bush ready to gank your victim, do a very good placement of your Dem St cause you can aoe stun and then pop your Golden Aegis to slow ur opponents down and even ulti to keep them bit more there. Oh forgot about the Bilgewater Cutlass you will have late game that will give additional slow that will be enough time to have ur Dem St+ Drag Strike combo available again.

Follow these basic cheats to make your allies fall in love with u. Really.

1st) Avoid placing your ulti in narrow paths that will block ur allies from chasing that annoying 10/0/4 guy down cause he may wait you to ulti so he pops flash + ghost witch is a pretty common chicken combo spell that can be devastating when used by smart players. (Even if you do this, be really really fast to already place a Demacian Standard to where the victim goes so you can dash out and stun him (and then pop ur shield to slow him) if he even tries to escape.

2nd) Place demacian standard when you break/kill things. Everyone's attack speed will go high. Yes you like hitting faster, DONT'T YOU? WAHAHAhahahahha -.- .. ok

3rd) Don't be a stupid KS'er with ur ulti unless you feel you won't have enough damage to kill that running foe by using ur dragon strike. (Tbh there's no such thing as KS, only matters opponents to die more than ur team. But It's also stupid to leave an opponent get away just because ur allie would go "omg u ks. i quit")

4th)

All in all this guide will help you make a support tank char that will dish out some damage while staying alive. Jarvan can be devastating and pretty annoying for the other team if played well. Avoid being heavily focused cause you'r not the kind of player that can hold tons of damage like amumu or rammus.
I hope you get familiar and pwn with this build. I will upload videos when I make some pretty good ones with Jarv.
Last note: Always remember, placing wards can help you literally teleport anywhere in the map and gank any squishy char. If other players get teleport too, you can massive gank anyone. Nobody does massive gank with tele + ward.
Have fun!
Theodore.