Word for a person who is overly demanding of artists

single-word-requests expressions literary-english

Sounds like you’re searching for "svengali".

The word "svengali" has come to refer to a person who, with evil intent, dominates, manipulates, and controls a creative person such as a singer or an actor.

source: https://en.wikipedia.org/wiki/Svengali

Related

When is it possible to form an adjective ending in "-onian"? Could we say "Marxonian"?
How to describe leaves growing
Using the word 'tiffin' to refer to a lunch box
Peculiar pronunciation of 'architecture'
Idiom for two people having two drastically different appraisals of an event
Usage and meaning of "up" in "...worth at least a thousand pounds up in London"
Do Canadians say 'go to hospital' or 'go to the hospital'?
Where, when, and how did the term 'dogie' for 'orphan calf' originate?
Should I use “speaker” or “loud speaker” to refer to the signal → vibration → sound thingy?
'Am I interpreting' vs 'Do I interpret'?
Which is correct: 'Drafty' or 'draughty'?
Usage on farewell remark