Found Guts's sword in Dark Souls 3 along with messages left by

Dark Sword Dark Souls 3 Wiki

Dark Souls 3 update nerfs the Dark Sword

Steam Community :: Guide :: Dark Souls III Complete Weapon Guide

Dark Souls 3 How to buff ANY Weapon with any spell.

Blade of the Darkmoon Pendant 2022

Dark Souls 3 Dark Sword Guide: The Best Weapon? – The Fuzzy Pen

This might be obvious but doesn't the onyx blade look like the hollows tried to recreate the firelink greatsword? : r/darksouls3

Dark Souls 3: The Best Strength Builds

Dark Souls 3: with Miyazaki back the future looks magical, Games

Crystal Blade Dark Souls 3 Wiki