Sword of Avowal

The Sword of Avowal is a key item in Dark Souls III.

Availability
Given to the player by a Londor pilgrim outside of Lord Gwyn's honorary tomb in Irithyll of the Boreal Valley, just before reaching Anor Londo.

Usage
Used to conclude Anri of Astora's questline.

Interacting with Anri's body in front of Gwyn's tomb will play a cutscene where the player plunges the sword into his/her body, concluding with this the rite of wedlock that will presage the coming of a true hollow lord.