I see what you are saying and that's why I corrected it. However, I wouldn't go as far to say as it MUST always because there could be a patch tomorrow that makes penetration quints more effective that penetration marks. It never dawned on me, in my 2 and a half years of playing, that penetration marks were more effective. Honestly, the swap didn't make much difference, in my eyes.

Here's a rule of thumb: If you run penetration, it MUST always be on marks. No exceptions. No play testing needed.

I'll update the scaling armor seals to flats then, although, I've found that using the scaling is better for myself. On the Armpen reds and AD Quints factors, that's an option for people who prefer more armor penetration. After play-testing it, I've found that it is more beneficial to use Armpen reds. Good call, thanks for elaborating. Also, thank you all for the help received so far.

Also, Scaling Armor Seals take 10 levels to surpass Flat Armor Seals. Considering that you don't even reach level 18 in all games, Flat Armor Seals are stronger for the majority of the game. If you also think about the possibility of level 1-3 jungle invades, you are more resilient for duels.

Armor is also an extremely easy stat to purchase, which means the effect of not taking Scaling Armor is pretty much negated over the course of the game.

tl;dr, Flat Armor is better than Scaling Armor Seals.

It's arpen reds and AD quints. Not AD reds and arpen quints.

Thanks, once again for your feedback! In most of my Jarvan games I do take Black Cleaver, but in this tank build, I want to squeeze the stats out of as many items as possible to create an efficient tank. The Black Cleaver does have health and CDR, but Spirit Visage also has Health Regen, Regen Bolster, and MR, which is more useful to that "full tank" feel. In my second build, the one that I sub Spirit of Golem for Zephyr, I found it more useful to gain the free extra movement speed and attack speed that Zephyr offers when paired with Black Cleaver is a definite plus to The Black Cleaver passive. In build 3, I use the lizard elder instead for the "AOE True Damage" aspect behind the build.

No problem. If you need cooldown reduction, Take Black Cleaver. It is a strong item on J4 right now. If you constantely have a blue buff through stealing or however means of obtaining, then you will always have at least 30-40% CDR. On the armor seals, I failed to note the armor increase from Demacian Standard. J4 can always deal good damage from the % health damage from his passive, so he doesn't have "weak autos". I would also recommend Spirit of the Ancient Golem for tenacity over any other tenacity item, but that's just my opinion.

Jungle monsters don't eat me, I can swear on that. The Jarvan IV build I created that utilized Spirit Visage had tons of Health Regen, thus I saw the Spirit Visage as a way of CDR/Health/MR, and an interesting passive that did do something, at least. That tanky version of Jarvan IV is also really strong against poke comps. Maw of Malmortius is an option that I included in the second build that I posted. Maw doesn't give CDR or Health though, so on the full tank Jarvan that depends solely on weak autos and Sunfire for damage, I figured the Spirit Visage was a better decision. I will definitely work on the walls of text thing. Thanks for the well-detailed advice!

Scaling seals will weaken your early game, meaning the jungle monsters will eat you alive.

Jarvan IV has no healing, so Spirit Visage is not very useful. If you need magic resist, buy a Maw of Malmortius.

Too many walls of text...check my signature.

Elaborate please... Simply telling me that the runes are wrong is of no help.

Wrong runes

Please leave any suggestions and feedback on my first guide. I'll be sure to take it into consideration!