“Might I suggest a google search of “God complex” which might convince you of the accepted terminology in the society in which you live.”....
If so, then to use a standard diagnostic term in a context which is not religious just might not be “blasphemy”.
May I suggest that “accepted terminology” that mocks the reality of the sacred has quite well diminished the society in which you live, and that “standard diagnostic term(s)” have done very little to advance the state of society which now gives you cause to strap on your pistol.
Please, go read the definitions and try to understand what the term describes. The term is used to describe those with delusions of grandeur, particularly those who think they are the latest visitation to Earth by God.
Psychosis exists, I am sorry to have to tell you. So long as patients consider themselves to be God, you must expect those who have to describe them to use well known nouns and adjectives to describe said patients.
Additionally, if the person doing the describing does not intend blasphemy, them minus “criminal intent” has a crime occurred?
Also, I am beginning to detect a rigidity in your parameters for discussion of anything even tangentially related to the word “God” which some may well find reminiscent of “DO not insult the Koran”.