MyBB Community Forums

In usergroup options/permissions theres an option saying "Yes, users of this group are super moderators",  what does that mean exactly? What permissions it gives? 

I want to make supermoderators unable to 'remove' a thread or post, I want them be able to soft-remove it but not entirely remove. How do I do that?

Super moderator users can moderate any forum

To disable thread delete permissions go to admin cp » Forum Management » Edit Forum > find Head moderator (or whatever you call your moderator group) then click on Set Custom Permissions and can edit them there

I want supermoderators unable to remove a thread, I want to change 'their' permission, not appointed normal moderator.

How do I do that?

Log into your forums ADMIN CONTROL PANEL.......
then.....

Look, that video is for moderators "assigned to" that forum. Supermoderators don't get "assigned to" anywhere, they have moderator permissions in entire forum, I am asking how do I change their permissions.