This is a quick guide on Season 11 Guide.Keep in mind this is my opinion/playstyle

With the season 11 items it's not as straight forward as going with one build anymore...So let me try to explain the different builds separating it into sections and hope it makes sense:

Zed against 2-3+ tanks:
I like to get my Eclipse first and work it an early executioners if needed.

If not last whisper into Serylda's Grudge.

After that it will be very dependent on the situation (check the list of viable items ill put at the end and choose the best for your situation).

Quick note: Ravenous Hydra is a super good item on Zed right now so it could be a great third.

Good full build: Eclipse, Serylda's Grudge/Black Cleaver, Ravenous Hydra, The Collector, Edge of Night.

2. Zed against squisher team:
Here I like to take Duskblade or Prowler's on preference, sidenote if they have a lot of kite Prowler can be clutch for a passive auto etc.

After that you want to get as much lethality as possible and not forget Executioner's into mortal reminder if needed.

Good Full Build: Dusk/Prowler's, Yoummu's, Edge of Night, Ravenous Hydra, The Collector.

Zed from behind:
I feel like when behind Zed does best with Eclipse but still not sure on this.

After that you will need to build according to needs: armor pen or healing reduction, a black cleaver to be a bit tankier and still do dmg to tankier targets etc.

All (or most) viable items for Zed:

Edge of Night

Yoummus Ghostblade

Umbral Glaive

The collector

Black Cleaver

Ravaneous Hydra

Lord Dominic Regards

Mortal Reminder

Death's Dance

Maw of Malmortius

Guardian Angel

Quicksilver Sash

If i forget any feel free to comment :)

Hope this helps, tried my best to make it as clear as possible!