Deleting items from dynamic list ASP Core MVC

I’m trying to remove or hide items from a list and I’m facing two problems, 1- the newly cannot be removed, 2- Tried to tag the deleted items as isDeleted = true using Javascript then later delete them in the controller following this answer https://stackoverflow.com/a/40572625/10773318 but it didn’t work.

How to dynamically add items from different entities to lists in ASP.NET Core MVC

This is my first experience with lists in general and I have kinda complex scenario. I want to add an object of type Story that has a list of Sentences that can be added dynamically. Sentence has a one-to-one relationship with Image and another one-to-one relationship with Audio (that are optional to add). I managed to add the sentences list to the database along with the story object. But I have no idea where to start with the other two entities.