Rudra had recieved a legacy parchment after he cleared the tier 3 promotion quest with a SSS rating.
The quality of the legacy parchment depended on the prior performance and achievements of a player , hence even if two people cleared the tier 3 promotion quest with a SSS rating , different rewards would be waiting for both people.
The legacy parchment was basically the AI giving the player access to information as to what it considered as the epitome of their class capabilities.
For example , if a legacy parchment was given to a assassin class , then it would contain a video of what the AI considered a near perfect individual who used the class skills in action.
Then a seperate video of how those skills were obtained and to be used will be given depending on the size of the legacy parchment that the user had got.