Talk:Ten Covenants/@comment-218.102.195.135-20140812163251

Volume 6 of the light Novel confirms that the 10 Pledges were not by originally by Tet, who instead only added the 10th pledge him/herself (which is why it seems so different).

The 9 Pledges were originally created by an Imanity call Riku, who is the main character of volume 6.