He knew it all along

The master that he had served to control his psychic powers as years gone by

Is really a fraud

For he had no psychic powers and that his office is just a cover

A cover for his new job

He hunts ghost

Yet he has fooled the people into believing that he can exorcise them in mundane ways

Such as editing a picture

Or giving them massages

As all these were remedies to exorcise an evil spirit haunting them

Despite his job, he is really a good guy

And a true friend