I remember this manga had the villainess remember her past only a week or something before judgement day, so she went around gathering evidence and making sure the 'heroines' allies don't show up to the banquet. I think her fiances brother was in love with her too. It felt like a villainess speed run.
this is the one that came to mind, but it's a day, not a week
https://www.mangago.zone/read-manga/with_one_day_left_i_ll_break_all_the_destruction_flags_serves_you_right_rta_24_hour_record/
This manga always makes me so happy, I hope we get more volumes in the future. I bought the manga at the bookstore last week!