Do something about Gunblade, Riot!

All information I got for this came from this site https://leagueoflegends.fandom.com/wiki/Hextech_Gunblade

Yeah there arent many champs, nowadays its pretty much only Katarina and Akali, that use Gunblade to begin with but those that do benefit to hard from it. Their kits' already insane damage get another AT LEAST ~235 magic damage thanks to Gunblades active (assuming you buy it earliest at lvl 9, giving it 211 damage by itself plus 24 damage from it's scaling and it's own AP.

It also grants assassins sustain, even in it's components, which they shouldn't have to begin with. Assassins need to be a more risky pick in general again and ridding them of their sustain is one way to do so. Playing a normal mage against them is nearly impossible due to it and if you dont give those a way to match their sustain you should take it away from the assassins. Hitting either of them in lane as a mage, which is hard enough to begin with, becomes meaningless when they just heal back up without even needing to use any resource that can run out.

So either reduce its ap scaling, its active's base damage and/or remove it's lifesteal/spellvamp passive. I would suggest swapping Bilgewater Cutlass for either Caulfield's Warhammer or Pickaxe (or Serrated Dirk for all I care) give it either 10% cdr or some leathality and reduce its cost to about 3000 gold total.