From FFXI Wiki
- Travel to Ranguemont Pass and head to the pool at E-5.
- Activating the Waters of Oblivion will spawn the NM Tros.
- Click on the Waters of Oblivion once Tros is defeated for a cutscene. At the conclusion of the cutscene you will receive your Paper Knife.
You do not need to be on Bard to activate the Waters of Oblivion, only to have the key item Mertaire's bracelet on you. Therefore, if you have a higher level job you can switch to that job and defeat Tros easily.