After careful consideration, Angor decided to make a covenant with Shadow.
Compared to swearing to the world's consciousness, a written magic covenant was better and more convenient for restricting apprentices.
To apprentices, who didn't know how to check the "integrity" of a contract by communicating with the world's consciousness, it was easy to leave "bugs" by using tricky words. This was why Angor chose to use a weaker but safer approach with Shadow.
Of course, Shadow could also attempt to leave defects when writing down a covenant. To prevent this, Angor was going to copy something he saw from a wizard magazine before, which had been proved to be almost perfect.
[Kurna's Agreement, Signed at the Crypt of the Tyrant of Despair]
With the hope of regulating each others' actions, an apprentice named Kurna created this contract with his companion before they explored the catacomb of an ancient wizard "Tyrant of Despair".