Ios – Subclassing a subclassed UIViewController that has a xib

I need to have a few UIViewControllers that look very similar yet have different behaviours, so I thought I'd make a general UIViewController subclass with a xib, then subclass it when I need to, for those different UIViewController's that look alike.

I'm trying to achieve the following

UIViewController subclass (that has a xib file associated) -> and being able to subclass it as many times as i'd like (without additional xib files for the children)

what I've done so far :

xib file represents a UIViewController with multiple UI Elements.

I've set all the connections to file's owner @ xib file.

the subclass with the xib contains this @ init method:

self = [[[NSBundle mainBundle] loadNibNamed:
                 [NSString stringWithFormat:@"ParentViewController"]
                                              owner:self options:nil] objectAtIndex:0];

when I connect the View property in the xib to file's owner I get an exception saying I can't
have the View property connected to both parent and child UIViewControllers.

yet when the View property is only connected to the UIViewController that the xib is associated with, I get a blank screen, and that outlet isn't disconnectable.

If I instantiate the parent vc instead of the child, everything works fine,
If everything is done programatically and not with a xib, also everything works fine.

since this UIViewController displays A LOT of UI elements, I'm trying to set it with a xib.

I just don't really understand how can I get the child ViewControllers to look like the parent's xib file and have their own additions and behaviours.