I really enjoy Ghostblade on Zed, that allow to snowball pretty fast if you already got some early kills.
But since i was laning versus olaf i didnt feel comfy enough to rush a ghostblade.
Also, from my personnal experience, duskblade isnt that strong on zed, it's better on talon than Zed.
Death dance is pretty good with a malmortius (and the BT that was coming), it allowed me to sustain in fight versus Olaf , or to handle Leblanc burst.
I could literally one shot Leblanc or Cayt (Btw i forced cayt to rush a QSS because she was dying only with my Ult + E Q).
Edit : Also tahm build ROFL.