Because I have no clue or I don't know if there is a feature here on Bitcointalk where I could just report this account and not each post?
Just use the report button and write details on comment box. If you can't report each posts then just report one and mention on comment to check that users post history. Moderators will do rest of the work from their side.
Edit - Someone have already given you the suggestion about report submission. Just follow that from next time.
As for the website itself, it was registered way back 2016 as I've checked on Whois. It may be an established site, so I suspect that account was used for "paid shilling".
Maybe some one is promoting their site to get payment from them but i haven't seen anything relates with that on their frontend. You can take a look on their
author's page and most of the authors profile have got no profile picture.