I Became the Younger Sister of a Regretful Obsessive Male Lead Chapter 4 Discussion

So far, this series is proving to be enjoyable if sad, read. Our MC has set herself a task to help her "brother" find a happy ending. However, the first obstacle is his dad that has a rather large amount of baggage (pretty standard fare for a lot of 'historic' BL series). I am looking to see how the series progresses, especially to see if the old duke can redeem himself.