User blog:One-Purpose77/Undertale AU question

This is my first blog so bear with me here. So I made my own account here maybe a year ago because I had a great idea for my own AU for the Undertale AU list but it got taken down but I realised my mistake. Recently I found out about an AU that I found interesting called Star Sanses so I checked it out and read all the comments about it. When I had looked at the AU's comments, I saw a lot of users saying that they loved the idea but the character choices didn't make sense (such as Blueberry Sans, Ink Sans, and Dream Sans becoming the Star Sanses). After looking over the Star Sanses AU page again and thought about the comments, I began to configure a different version that would fit the idea of what the commenters were talking about. I never posted the AU but I have written everything down. Someone in the comments said that because the character choices, and that it is not pronounced as canon yet, the AU doesn't make sense and there is basically a big hole in the AU that says "placeholder". My question is, can I make this new version of this AU and post it but give credit to the original creator also since they thought of it first? I'm not trying to steal their idea, I just want to improve it.