A psychic master is not a master in the "master-slave" sense. A psychic master does not enslave anyone or anything. Furthermore, a psychic master does not even 'own' or 'possess' anything - not even himself.
There are those who approach the psychic or spiritual with these ideas of conquest and ego-feeding; they don't get very far. 'Being', rather than owning or enslaving is the key idea. Love and respect can take you much further.
Although a psychic master perfected many psychic techniques, that's not what makes him or her a master. Mastery of technique means simply that one is a specialist. Wasting your talents on proving that you are talented do not make you a master.
If you want to recognize a master, look for simplicity and elegance. A psychic master is very clear what his goals are and does not waste effort on confusion and struggle. It is not so much about the simplicity and elegance of psychic techniques, but the simplicity and elegance of knowing when and how to use them.
A psychic master does not only seek perfection, but also decides what perfection is.