So I got some ideas I want to share with you all after some thinking
Idea 1: Take the idea of Bowser Jr's journey, except replace the plot of Bowser Jr and the Koopalings finding a alternative Blorbs cure and instead helping Bowser and Chrysalis deal with Fawfuls army on the sidelines in the beginning
In the story I intend for Jr and the Koopalings to be siblings, Koopalings adopted obviously, so while they do fight, they still love each other, they are family