"whatever satisfies his purpose" or "anything he wants to do"
# No one can stop him
It may be helpful to add additional detail. AT: "When he decides to do something, no one can stop him" (See: [[rc://en/ta/man/translate/figs-explicit]])
# No one can say to him, 'Why have you done this?'
This can be stated as an indirect quotation. AT: "No one can question what he does." (See: [[rc://en/ta/man/translate/figs-quotations]])