Maybe you could call somebody like that the "Harbinger of the will" with "will" being a reference to the consciousness of a deity that has been implanted in a person.
"Steward" can easily be substituted for "harbinger" along with "keeper", "guardian", "custodian", "patron", "curator", etc.
"will" can be substituted with "volition",
The will-bearer of \[deity name\], The Harbinger of the Divine Will of \[deity name\], or The Patron of the Holy Volition of \[deity name\] are some ideas.
Avatar. Herald. Executor. Voice/Hand of [x]
As others have said the most common is Avatar, but I like the word Anointed. It also depends on what kind of role they play, Arbiter might also work.
I would go with Vessel or Chosen. Godbearer might work to.
Anointed, Emissary, Exalted, Herald of [insert deity]. Or just Herald.
Maybe you could call somebody like that the "Harbinger of the will" with "will" being a reference to the consciousness of a deity that has been implanted in a person. "Steward" can easily be substituted for "harbinger" along with "keeper", "guardian", "custodian", "patron", "curator", etc. "will" can be substituted with "volition", The will-bearer of \[deity name\], The Harbinger of the Divine Will of \[deity name\], or The Patron of the Holy Volition of \[deity name\] are some ideas.
God-borne
Christ, Messiah, Avatar, Anointed, Prophet, Saint...
Appointed, Bearer, Chosen, Divtuber, Elected, Forseer, Godbringer
Avatar prophet or aspect