Hi, my name is Flippant God on the NA servers. This is also my first guide. I'm currently Silver 5, which makes you wonder, why should you listen to me? I have tried this build back in season 3, and it dealt quite the damage, and with patch 4.10 I believe the AD item buffs will make this damage output significantly better. Every build should be given a try. Try this in normals. Maybe you'll like it, or maybe you won't. I personally favor this is my go to build if I want to nuke people to death.

Not many people pick Jayce for any game nowadays, and seeing the decline in Jayce made me wonder, why is it so bad? In my opinion, his W is the best attack speed buff there is, and spamming his ult makes it great for the escape. His hammer form passive gives him mana, and with lifesteal items, he can technically stay in lane FOREVER. Jayce in my opinion, is one of the best AD casters there are, and in the bot lane, is W will allow him to excel in trades, and his Q is an excellent form of poke.

Pros:
-One of the best attack speed buffs there are.
-Great mana sustain
-Long ranged Q poke that also reveals.
-Hammer form E is great self peel.
-Ult is great for escapes.
Cons:
-Squishy as an ADC can be.
-High skill cap
-Item dependent

Jayce can leap to jungle camps by using Q in cannon form to reveal the monsters, then quickly pressing his ult to change to hammer form, then use Q to leap over the walls.

His E in cannon form can be used as utility like a Sivir ult.

I hope that you found this guide useful, and hopefully you'll see Jayce in a new light. I would like to see him played much more often, and not have someone complain when I (or anyone) pick Jayce and dodge. Goodbye! :D