Waterdeep:House Auvryndar

House Auvryndar is a minor drow house from Menzoberranzan. You have encountered their members several times within Undermountain.

Arcane Chambers

Within the Arcane Chambers you met Rizzeryl Auvryndar. While a member of the drow house, he was in the Arcane Chambers doing contract work on behalf of the Zhentarim in order to hinder the activities on the Xanathar Guild there. You obtained the key to operate the Gate of the Penitent Dwarf connecting Lost Level with Slitherswamp from him, as well as a map of the Arcane Chambers.

Sargauth Level

Sargauth Level was disputed territory between House Auvryndar (led by the priestess of Lolth, T'rissa Auvryndar) and the Legion of Azrok (led by Warlord Azrok). You slew T'rissa in a pitched battle and cleared the drow-controlled territory so that Azrok's legion could move in.

Twisted Caverns

A small contingent of Auvryndar drow were occupying the Twisted Caverns and trying unsuccessfully to deal with the aboleth which had taken up residence there. Nearby, House Auvryndar was building a housing project, which may explain the drow trying to push back against the aboleth.

In the Auvryndar Housing Project, you ran into Rizzeryl once again, and slew him.