This is driving me crazy... I need another pair of eyes on this to help me
Therefore...
Here's a sample project demonstrating my case.
Just open the project in the editor, Test, then open console with F8.
Talk to the only NPC on the map and pay attention to the console when the battle starts.
You will see I log the Sprite_Enemy object, which includes a Parent property
that is not null, but when I log just the parent object it returns null.
For more info dive into the u.js plugin file in the project.
Here's the sample project:
https://dl.dropboxusercontent.com/u/46654731/NullParentLog.zip