I disagree ,manamune delays jayce's early game powerspike in sake of late game .I also mentioned it at possible items, I ask you to reconsider your downvote, as manamune's early stats are inferior to essence reaver.

Downvoted because Maraune is a must on jayce he gets a huuuge power spike with it

I play on the TR server, sadly enough the only server I can't get my league verified on,I will go ahead and keep working on this ,adding matchups ,have a whole empty day today.

You're slowly getting better and better with the coding :) Keep it up and don't forget to add explanations to everything!

You have no idea how long it actually took me to code all of my guide, lol.

Btw, what server is that you play on?

Thank you for you feedback !
Typo has been fixed,I'll add the items in second ,They may be added by the time you read this.
I thought I mentioned maxing e second for health stackers but turns out I didn't,also added.
I never really play ARAM's or dominion but I'll see what I can do about it.

In the notes of the abilities sequence, you said "Max Q fof" (being a Nazi).

You could add the Iceborn Gauntlet as an option, if you felt the need of buying a Sheen to harass your opponent in lane with W-boosted AAs, but felt behind and couldn't use the Trinity.
On ARAM/Dominion, Entropy is quite good to play, for endless kiting, tankiness and AP.
Also, since it's a blue Build, Frozen Mallet is a fine pick.

About the ability sequence, Jayce may want to pick E second to deal some damage to HP-stackers (think Mundo/Zac/Cho'Gath).

Have a radiant day!