The PC must have taken the Kill Riurry quest for Riurry to appear.
Description and walkthrough[edit source]
After chatting with Riurry, the PC must return to Yrriur and kill her. When chatted with, Yrriur will tell the PC not to listen to her evil half. Yrriur is a surprisingly nasty opponent, with enormous DV and an incredibly powerful melee attack, making her somewhat risky to engage in melee with. The player should also be aware that, of course, this is a highly chaotic quest; attacking and killing a greater white unicorn brings a huge alignment drop in itself.
When the PC chats to Riurry after slaying the greater white unicorn, he will reward him/her with a pile of 3d3 (3-9) potion of gain attributes and an amulet of chaos. He will also 'grant' the PC 0-2 corruptions.