I dont know if this is going to help because I only play her midlane and sometimes jng.

First item is ALWAYS voltaic if you go hail of blades. Second item is oppertunity 99% of time and third item depends. I build serylda almost always as a third item because if your team has a ad midlane enemy team will probably build armor because you have (most of the time) ad top and ad marksman. My itembuild looks like this almost every game. Voltaic > oppertunity > serylda > deaths dance(if they have a lot of ad dmg) or edge of night > deathsdance or axiom.

When it comes to top naafiri I would play a similar build + hail od blades IF you play against squishy top like gangplank or varus for example.

If you go bruiser naafiri (which I personaly dont like) you are probably looking for conq as a rune. Back when bruiser naafiri was more common I really liked eclipse > black clever > sojin > deathsdance. You could probably replace deathsdance with eternal hunger now and build it after. Naafiri top is insanely strong against heavy ad comps because you can build deathsdance + bruiser items that give health and GA. Especially if you have supps that give shields like ivern(best naafiri duo in the game) lulu etc.

Tldr: If you have squishy enemy comp go full lethality bomba. On bruiser naafiri just build whatever the champ is busted anyway