Over at a wiki, I am administrating, there's a fellow admin/bureaucrat.
Back when the wiki was abandoned, they started out being nice and helpful and both of us wanted to apply for wiki adoption. Back then, I promised, that I would give them admin/bureaucrat rights, too, once I would be able to adopt the wiki.
The adoption was successful and for almost a month everything was going nicely.
But around roughly a week ago, he started abusing his rights to vandalize other users' comments and user pages by turning the meanings of their sayings around or making them make fools out of themselves.
He also promoted another user to admin/bureaucrat status, despite the other user not having proven, that they are to be trusted and them being blocked at another wiki.
Now I have no idea how to deal with the vandalizing admin and I am afraid, that the other one might join in, too, if they were to be more active.
Does anyone know how I can deal with this?