General skill leveling guide - Max E, choose between Q and W depending on situation. Q for better harassment, W for sustaining.
Brawlers Glove + Red pot for start. Depending on lane situation, get:
A) Avarice if you are planning to passively lane.
B) Executioner's for aggressive laning, there is a on hit proc damage DoT. It works on Parley, so every parley deals 32 more damage overtime. If you manage to get 1 melee hit off the enemy, you will deal about 100 extra damage with EC and your passive. And you heal yourself slightly with every minion kill. EC active on enemy when they red pot.
Once you have your EC and Ghostblade, you can deal massive damage in teamfight by popping E and Ghostblade active. Assume you're level 9 and without any runes, your dps in a 6 second period will be 179. Note that this does not include the damage from your parley spamming and ultimate's cannon ball, nor the 30-40% crit chance.
You will be able to survive better with lifesteal from EC, if you're farmed enough to have Visage, not only you heal more from Scurvy (W), your lifesteal also benefits from it. Plus the fact that Youmuu, Vistage provides 25% CDR, combine with CDR boot, you will be able to reach 40% CDR Cap. Allowing you to use E very often, and spam Parley every 3 seconds (It is very useful if you have Tri-froce/Red buff)
Is the remake a nerf or a buff? It is arguable. It is highly unlikely he will be changed in the next 2 weeks (or even another 6 months), so maybe we should just deal with it.
I do see a lot of potential in his massively changed E. 68 AD steroid combines with AS item, especially the 50% AS steroid from Ghostblade active seems like a perfect match for burst dps power. Although he is squishy if he is to get into melee range, giving him health + MR + lifesteal + a buffed W should be able to solve most problem.
He can't be kited easily too because he is running with 30% MS buff from E and 20% MS buff from ghost blade, plus a global guarantee slow from his ultimate, and a free cleanse to counter CC.
I only try this a few times, works decently. Maybe this build is not exclusive to GP (I can already imagine Irelia being able to use this LOL). Nevertheless this is my take on how to build the remade GP. Please try it and comment.