Mordred

Mordred was a Knight of the Round Table who rebelled against King Arthur. According to the Tau'ri legends, Mordred and Arthur mortally wounded each other at the Battle of Camlann. However, the people of Camelot said that Arthur survived the battle, killing Mordred.

When Myrddin awoke from stasis, in a daze, he believed that Ba'al was Mordred. After hearing his insolent talking, he used his powers to manipulate Ba'al's vocal cords, causing him to lose the ability to speak.