Can only think of portals atm, since creating portals means manipulating the boundaries of spacetime

To me it's simple it's like switching a switch since boundaries represent difference you could make something real by removing the boundary from it's unreal status and vice versa make something real fake

You can also manipulate the boundary between creation and destruction to influence creation and create things. Same with existence/nonexistence, reality/fiction, nothingness/completeness etc

Thank you guys for your answers. I was also thinking about like you could make yourself be immune to harm by defining a boundary that separates you from damage.

@AzQth what do you thinking about the creating aspect of Boundary Manipulation?

I feel deja vu

Seems like someone manipulated the boundary of your memories and your imagination lol /j