Can I edit Content Y within Content X Edit Form using Rules? I have created a content type VIP PAGE, and another content VIP IMAGE. Now I want to allow the user to upload 5 VIP IMAGES at the same time as creating the VIP PAGE content. 

So what I did was to add 5 Image fields to the VIP PAGE content type, then I created 5 Rules, which trigger when content type of VIP PAGE is created and it takes those 5 images and creates 5 VIP IMAGES content and uses Entity Reference field to connect the IMAGES to the PAGE.

Now this all works fine, until a user decides to Edit one of their images. I want to still use a single page (VIP PAGE Edit Form) to handle images being edited. Can anyone recommend a good way to achieve this?

I can't figure out how to tell Rules which of the images it is that was edited.
Entity reference and Inline entity form could help you.


Entity Reference:


  Provides a field type that can reference arbitrary entities:
  
  
  A generic entity reference field
  Four widgets:
  
  
  Two implemented on top of the Options module (Select and Radios/Checkboxes)
  Two autocomplete widgets (one with one text field per entry, one tag-style with comma-separated entries in the same text field)
  
  Two formatters:
  
  
  A "Label" formatter, with optional link that displays the label of the referenced entity (the node title, the user name, etc.)
  A "Rendered entity" formatter, that renders the references entity using a configurable view mode.
  
  Integration with Views (for both forward and backward references).
  Integration with Entity Metadata (and as a consequence with Search API and the like).
  Integration with Devel generate.
  Integration with Feeds and Migrate (>= 2.3) for painless data import.
  

Inline Entity Form:


  Provides a widget for inline management (creation, modification, removal) of referenced entities.
  The primary use case is the parent -> children one (product display -> products, order -> line items, etc.), where the child entities are never managed outside the parent form.
  Existing entities can also be referenced. Supports commerce_product_reference, commerce_line_item_reference and entity reference fields. Read the documentation here.