How about instead of fighter and ADC Itemization we address the zero itemization that assassins have

Seriously Take a look at LB,Rengar, and Zed.

They don't have their own types of items instead they buy items that go good on other types of champs.

Rengar buys Fighter Items then puts out assassin level damage and is tanky like a fighter.

Zed Buys Melee ADC items then dives in throws out a couple spells and his ulti and passive do the rest of the work.

Leblanc buys Items for mages and then obliterates you in under a few seconds and has the mobility to escape nearly anything you throw at her.

My point is these champs are being carried by the damage off their spells but are getting items that are more efficient on champs who don't have as great of scaling. They buy these items and then they come in and wreck you in close to just under 1-3 seconds and alot of times even less than that. I just played against a rengar (and got stomped) as MF who got murdered in literally the split second it took him to appear. He did over 3900 damage to me in under 1.5 seconds which was overkill for my measly little 1900 health pool. I don't mind Assassins having big damage but when they buy items that say go great on sustained damage champs say Jarvan for example and then turn around and put out 3x the damage in a fourth of the time then i have a problem.

I feel like Assassins need a few items that specifically benefit their style of play instead of buying stuff like say for example Black cleaver and then just doing obscene amounts of damage in split second intervals.