On the subject of Clarent. You probably know this, but I’m going to use you as a prompt for writing about it.
The blade didn’t gain its name of “The Traitor’s Blade” until after it was used to kill King Arthur. Before then it was a “sword of peace” used for knighting ceremonies and other formal occasions, serving as a symbol of King Arthur’s sovereignty.
Originally the blade came from King Uther and Merlin, who either used one of Uther’s swords or crafted it himself to prove Arthur’s linage, embedding it with magic and sinking it into a stone from which only the rightful king could draw it.
In all likelihood, the only ones capable of using Clarent would be Merlin, Arthur, Mordred, and any other children that Arthur has.