Sounds like typical male veiled behavior. Males are either very nice or "not-so-nice". The hissing and charging you is a way to tell you to back off. It is working with you. As spencer k stated, they usually don't bite, but when they do it can hurt a bit. Try urging him with a stick. Or you can come from the top and using your thumb and index finger grap him right behind the head(He won't be able to bite you if you do it right.) With the other hand, gently loosen his grip from the branch and put him on your hand, letting him to grab on your fingers. Let go slowly with the hand you grabbed him with and he should be ok. He may hiss once or twice, but when he realizes you are not going to hurt him, he will settle down.