Many people, especially in lower rankings, think that they're the best and need to carry their teams if they want to climb out of (Insert rank here). Mathematically speaking, you have an 80% chance of being wrong. But that doesn't have to stop you from being a massive contribution to your team. League of Legends is a team game, and the best way to win is to work as a team. This means grouping up and jumping on the poor chumps that are on the wrong end of the map and obliterating them, ending their feeble lives for 20-70 seconds. This means you need "Engage", or Initiation. One of the strongest initiators in the game, and my favorite, is Jarvan IV, or as I like to call him, Jarmancia.

Pros

Strong fighter
Strong Jungler
Strong ganks
Stronk
Powerful initiation
Gets very tanky, even if built glass cannon
Does a lot of damage, even if built full tank
His initiation is his escape
Game changing ult
Manly, hairy chest under his chestplate

Cons

Sometimes too manly for his own good
Slower clears
No natural sustain
Can fall behind, and slower to catch up
His escape is his initiation
His ultimate can hurt your team a lot if you botch it up

Marks (Reds)
> 8 Armor Pen
> 1 Crit Strike

Seals (Yellows)
> 9 Armor
> Flat health is acceptable now that they buffed those and nerfed armors, I'm going to experiment with it soon

Glyphs (Blue)
> 6 Flat Cooldown Reduction
> 3 Flat Magic Resist

Quints
> 3 Flat Damage

Explanation

I like the armor pen reds because your passive does physical damage, so the more it punches through the better, as well as your Q and R. Basically, you do a lot of physical damage and its good when it hurts people. That one crit rune is nice because sometimes it hits jungle creeps, which makes it a really easy clear, or even better an enemy champion. Putting that one crit rune in allows Brasil to shine its glory upon you and win you the game.

Yellows are standard, those are your defensive runes and help you not-die. Jungle creeps do physical damage, so armor helps you clear while taking less damage. These have been nerfed by about 30% of their value, and health runes have been buffed. You can try those, I probably will maybe later.

Blues are generally used for MR, but in the jungle you don't take magic damage. By the time you're out of the jungle and in to the lane, it's late-mid game and an extra 7ish MR won't help too much. 5% CDR does, however. It makes clears easier, and you'll be able to gank faster. That's a matter of preference though.

Quints are big, expensive, and important. Jarman ha a naturally high move speed, so Move speed quints aren't too necessary. Since I opted for Armor pen reds, the flat AD quints are necessary to help massacre the jungle and end the lives of your enemies. If you choose to have quints that aren't AD, you'll need AD instead of armor pen reds.

Summoners: Flash Smite. Smite flash is acceptable.
Jarvan IV's first attack on a target deals 6% / 8% / 10% of their current health as bonus physical damage. This caps at 400 damage. This effect cannot occur on the same target more than once every 6 seconds.
Really good at hurting things. You take big buffs fast, and your first whack (Debatably the most important) hurts a lot. Make sure you get a Q off before you attack to make sure you get the most damage.

ACTIVE: Jarvan IV extends his lance in a straight line, dealing physical damage and lowering the armor of all enemies hit for 3 seconds.
Additionally, if the lance connects with a deployed Demacian Standard, it will pull Jarvan to it, knocking up enemies within 180 range along his path for 0.75 seconds.

This combined with your E is your everything. Your initiation, your escape, your gank, your damage, your peel, your clears, your objective steals, everything. It's on about half the cooldown of your E at rank 5 though, so it can be used to dash to your flag twice before you flag fades away, or hurt people. Go for hurting people. Hurting people is good.
ACTIVE: Jarvan IV slows enemies within range for 2 seconds and shields himself for up to 5 seconds. The shield gains strength for each enemy champion within range upon activation.
Basically a Randuin's on your W. The shield is cute, and at rank 5 in the middle of their team it actually blocks almost something. Get this at level 4 for the slow, that's its real purpose.
PASSIVE: Permanently grants Jarvan IV bonus armor and attack speed.
ARMOR: 10 / 13 / 16 / 19 / 22
ATTACK SPEED: 10 / 13 / 16 / 19 / 22%
ACTIVE: Jarvan IV throws a Demacian flag to the target location, dealing magic damage to enemies within 75 range. The flag will remain for 8 seconds, providing an aura that increases the attack speed of allies within a radius of 600.
I included the armor and AS because it's important to see the stats gotten. The gap between rank 0 and rank 1 is almost as big as the gap between rank 1 and rank 5. That means max this second, you get more stats per level with your Q then your E, but it's still important to get your E first, and when you drop your flag you get double stats so basically rank 1 dropped flag is as strong as rank 5 flag in your pocket.

ACTIVE: Jarvan IV leaps to an enemy champion, dealing physical damage to it and creating a 325-radius circle of impassable terrain around themselves. This circle lasts for 3.5 seconds and also grants sight within 825 range. Jarvan IV can prematurely destroy the impassable terrain by activating this ability again.
Actual in game text says *Heroically*. Just to show you how manly this champion is. HEROICALLY jumps on a punk. This skill is what makes Jarvan, JarMAN. The whole *Impassable* terrain is a bit exaggerated. Vayne can tumble through it, and every now and then you can just walk through it. 99% of the time though, its a death arena for your FISTICUFFS! It does very nice damage, but its the walls of pain that matters. Use this in a team fight to cut their team in half, cut off an escape, or make an escape for your team. Get fancy, practice it.

What I love about Jarman is he can be built so many ways. You can build more damage if you have a tanky team and need more murder, or tankier if it's the opposite.

I've tried [Feral Flare] on Jarvan and yes he does some good dam-a-jes with it, I like [Spirit of the Elder Lizard] much much more. He needs that jungle sustain, and he will have mana problems if you don't have blue buff so a Spirit stone item will help immensely with that. Jarvan has strong ganking potential, and I feel that spending so much time in the jungle farming up the flare is a waste.

[Black Cleaver] is a great item on AD bruisers, it gives Jarvan a ton of needed stats, and the armor shred is hot.

[Frozen mallet] is my favorite item in the game, it's just too manly to not get. FroMal says "I'm going to punch you and you're not going to run away, MAN UP AND FIGHT!". 700 Hp is nothing to scoff at, and it gives a meaty chunk of damage.

[Randuin's Omen] gives tons of armor, hp, and the slow in combination with his shield means even if he doesn't ult, your team ain't going anywhere.

[Locket of the Iron Solari] is stronger now that it builds out of null magic mantle. The team shield is nice too, because why not.

[Boots of mobility] are good since you gank so much, and you can always sell them out for other boots.

Randuins is your core armor, Locket your core MR. Feral flare is your core damage and although I say Black Cleaver is always worth, it can be substituted out for something else if needed. If you need to swap something out, drop the FroMall. It's rather expensive and the only defensive stat it gives is raw health. If you need MR, pick up a , or if you need armor is a manly substitute.

Jarvan is goin be creepin all over yo team. As soon as Jarvan hits level 2, he has cc and dam-a-jes. Generally you want to get blue buff because Jarman WILL go OOM, and you can't spell Mana without Man, so no mana no man. After that grab wolves, and then head to red buff and murder it and its family. After that you'll be level 3, so put that second point in to Q and look to kill a lane. Bot lane is always risky because 1v2 (Top or mid) is easier than 3v2. Mathematically speaking, in top or mid you have 100% power over your enemy (generally speaking). Bot lane you only have an additional 50%, so you as a jungle are worth more top or mid lane then bot lane until later on.

If top or mid aren't in good position go ahead and clear golems/wraiths, and kill the other if you still can't get a gank. Jarvan is a powerful Feral Flare jungler, but he also has crazy strong ganks starting from level 2. It may be difficult to balance farming and ganking, so the best advice I have is keep your eye on the minimap. Ganking should be your priority though, since Jarvan's ganks are better than his clears. If you can get an early lantern, do it but try and get your lanes winning.

Once you have an ultimate, you can start catching people out. Your ganks are stong and you have strong dive potential, and Brasil help the poor soul that dares over extend. After laning phase, if you're ahead try and force fights with the enemy by ulting their carry and anyone else near by. This makes it easy as pie for your team to AoE them and land skill shots. Jarvan also does a ton of damage, especially with a flare/Cleaver, so you can definitely murder their carry in your Arena of I Dont Care How Well You Think You Can Kite. Try and wait until their carry burns their escape/flash, because your Ult can hurt your team as much as it hurts the enemy.

If you're behind, your ultimate is a great tool to catch out the enemy and get your team back on track. If y're clever, you can also use the ult as an escape. The best way to do that is to drop your flag close by, ult a nearby enemy (For best results use this in the jungle), then Q to your flag and bust *** out. If need be, use flash but you shouldn't need to. If done right, who ever you ulted has to flash over 1 wall to get to you, and anyone caught behind the arena has two walls to flash through. Just be careful to not trap your carries in your ultimate.

Manly champions win games. Jarman is manly. Do it.