@zlax Please tag the other moderators in this discussion for transparency sake: @Surasanji and @arteteco
In my opinion if he wishes to mute you that is his choice. I do agree it is a bit odd that he follows you and has you muted but in and of itself I'm not sure thats an issue.
If he follows lots of people just for the sake of SEO that would be concerning, I agree. But he follows only 77 people and has 95 followers. So it does not appear on my end that he is mass following people for the sake of SEO, I could be mistaken of course, but based on his follower count alone this isnt evident.
If i understand correctly your primary concern is that he follows you but has you muted, so doesnt wish to actually engage you. Since he isnt mass following people how would this even act to his advantage in any way?