say hello to the great tanky/ dps, Jarvin IV.

The 21 8 1 build was basically taken from phreak and his champion spotlight but it really does give him a great damage output with some defense and can chase easier, or escape, with the 1 in ghost.

killing spree Jarvin's early game has some great damage mainly because of his passive, so your whole build should start out more defensive with mercs and catylist.
rampage Now you have some health and resistance, time to build atma's for more damage. when you building atma's, I sometimes need some more health so i get a cheap ruby crystal in between cloak of agility and chain vest but its your choice.
unstoppable After atma's continue building on the ruby crystal with giants belt and regrowth pendant to make warmogs.Then, finish out the catylist and with banshees vail.

Now your basic build is finished and the next 2 items are situational slots depending on the other team comp.

dominatingThe first slot is more offense and you can choose between frozen mallet for more basic damage, which will happen more often, or you can get last whisper if your having trouble with a tank.
God likeThe last slot is a defensive slot which can be filled with either thorn mail or force of nature depending on which carry you are having trouble with.

If your fed and you are not having trouble with defense then just get both offensive items. same goes for defensive if your in deep need of it.

advice #1right now i see people using dragon strike as a harassing ability and this is a BIG no no. if you want to harass, use the flag. It has decent damage, bigger range and it buffs your allies just in case. The only reason you use dragon strike is to be able to use the cc move or maybe kill in this rare situation that dragon strike is the only move off CD and your chasing someone that has like 1 health left. otherwise, wait until it comes off CD and cc that bastard.
Adivice #2 Jarvin is a great ganker and activator for team fights. This is the reason you build him as a tank. while both teams are going back and forth, try to get that poor bastard that extends to much in your ult, otherwise, when you initiate officially, start out with the flag, dragon strike to it, and shield to slow everyone around you down and protect you at the same time.
key advice NEVER USE YOUR ULT IN THE MIDDLE OF A TEAM FIGHT. You could just make things worse for your teammates as they die in your ult. Only use it when the teams are on the move to trap someone for your team to nuke down easily. YOUR ULT IS COMPLETELY SITUATIONAL AND NOT WHENEVER YOU WANT.
advice #4 The greatest part of this build is you are pretty durable even with low health because of this item build and golden aegis, so when they think they can kill near your tower, use your shield, ult them, and cc them until they die and you will be laughing at them afterward.

Remember that your passive does 10% of your opponents current health every 6 secs so remember you can last hit a little earlier then most champs. If you wanna push hard, maximize your output by hitting all the minions with that 10% boost in damage.

I can play malphite also and what i noticed is that Jarvins cc move is almost as good as malph's ult except Jarvin can use it a lot more often. Malph's is a bit bigger then his but like i said, Jarvin can use it a lot more often.

In the laning phase i have found that Jarvin plays very well with other characters that have a dash and stun like Renekton and Irelia. Remember that you are Jarvin, you have a great deal of cc and durability so stay at the front of your team to activate.