Gather Horus' Feather and a Medal of Triumph, then right-click to create Feather Pen and take it to Verdandi.
Medal of Triumph can be obtained in Lava Heights or from the Fallen Darkness event.

Show Quest Info

Introduction

Verdandi suggests crafting a Feather Pen by using Horus' Feather and a Medal of Triumph.

NPC Dialog

I-in order to use Hades Ink... y-you'll need a pen
made from Horus' Feather. Try... u-using your
crafting skills to combine it with a Medal of Triumph.

Quest Completion

Wow! You... r-really are good! I suppose... I should
bless it now, heh.