Changing position of vertexes of instance objects without affecting the source object

Hi guys,

i want to change the postition of certain vertexes from duplicate instance objects, while at the same time not affecting, or better said keeping the object hierarchy so that all objects can be changed at any time.

Or lets say, i want one object to be the “original” and will change all others if modified, BUT at the same time, i want the “daughter” objects to be edited with their own vertex positions.
I dont delete or add vertexes, i only move the position of the vertexes.

Right now you can only make instances, and then when you modify, you will ALWAYS modify all objects, no matter which one you click and edit.

I hope to have explained it clearly.