If you delete your entire post, of course the activity and rank will decrease and the merit will remain. I think the OP wants to delete his entire post because he has participated in the campaign most of the posts there. But OP you don't need to delete your posts because no one will care about your campaign posts if you do it right. 'OP' you may not know that even if you delete your posts, your posts will remain https://ninjastic.space/user/swiftxi?merits. But I want to tell you what made you think of deleting all your posts? I saw that many posts have already been deleted, your total number of posts was 254, but right now your post is 201?