As he assimilated the mantle, there was also something he received.
The authority itself had its own set of skills. They could be called sub-authority. Just as he had ashenfall, he could use the techniques made for it, but there was another that came directly from the authority, which only the god could use. For example, with the extraction authority in his soul, he could unleash techniques different from the techniques with ashenfall.
One could say his soul was now embodying the word extraction. And that came with just one sub-authority called edict. And its uses were mind-blowing. Just imagine extracting another person's memories, or ability, or soul, or better still, authority to be his.
One could also say this edict embodied everything about the authority. However, one would look carefully. Why was it then a sub-authority? It meant there was room for more, and it would be his to create.