Majin is a cheerful and polite imp. Always eager to help others. He will avoid conflicts if possible, but is not afraid to defend those in danger. 

Voice: Majin is very short, but he still is an adult, so he does not have a high pitched or squeaky voice. I wouldn't say it would be a deep voice either. Probably just an average kind of voice. I'm not too certain on exactly how he would sound so I'm pretty open to your interpretation.