That is, of course, up to his discretion and no rules have been established thus far, either. If rules are to be established I have the reasonable expectation they would be pinned at the top or placed somewhere hard to miss.
Joker and Mishima are practically in the same field of expertise. Plus, I know Joker in reality and he's been a natural born leader...whether he wanted it or not.
Mishima, take this opportunity to establish loose rules, or begin working on a link to them. Only very loose rules, as the community should be laissez-faire though there is such a thing as unacceptable behavior.
