Riot, This has to be addressed asap

Jayce ever since his release has been a nightmare for top laners. His Kit is a hideous overloaded amalgamation of very few counter-play mechanics. He has seen good days and bad days as the meta shifted and new item changes, masteries, champions etc got introduced. But those "bad days" never got to a point worse than "hes simply not optimal/meta". The advent of the new seasons masteries along with item changes have only catapaulted his overall strength as a lane bully and as a late game hyper carry.

With the recent Duskblade changes it isn't out of the realm of possibility that Jayce can one combo you with just his melee form if you are anything short of tanky. Late game he just needs to hit you with his ranged q, then melee form q and aa. As absurd as his late game damage is, i would be fine with it if Jayce subscribed to the tenets of riots design and balance team(or rather what they aim for supposedly), namely "to have clear strengths and weaknesses along with having windows of opportunities".

Clearly this is not the case as Jayce is good at all stages of the game. His few weaknesses were circumvented by the mastery(Stormraiders lel) and item(ESPECIALLY CDR) updates. The fact that the role he sees most play in is top lane only serves to keep the time he is weak minimal. At the current moment top is primarily melee champs, with most of these melees(barring a few broken exceptions i.e. pantheon riven) struggling against ranged bullies. Typically good game design would entail that a melee champ would naturally get bullied by a ranged champ early on, but if a melee champ were to ever close the gap they would be rewarded with either out-damaging or straight up killing the ranged champion with their superior stats.

Jayce is one of those few champions that actually PUNISHES you for closing the gap on him, as he will switch to melee form, combo you for at least 30 percent of your health then knock you away, and summarily switch back to ranged form and harass the ever loving shit out of you for having dared to try to trade back damage. Late game, he will most likely obliterate you before you can get close to killing him. Basically, the window of opportunity on Jayce is too small to for him to have a "healthy kit" ,cause as of now, the only way most melee champs beat Jayce is if either the player is bad or you get your jungler to camp him. Riven and Kennen share this same problem, but thats a topic for another day.

Now i know most people and riot don't think of Jayces current state as a legitimate problem since he isnt being played enough to be noticed on the radar, but i will say this: A Jayce that knows what he is doing has very few counterplay options top and is extremely unfun to play against.

tl:dr: Jayce needs some meaningful nerfs, considering how much all the item and mastery changes helped him, so that he doesnt have a god like late game while bypassing his only windows of weakness by being an oppressive hyper-scaling lane bully.